Articles

Supermarine Walrus making a deck landing

Supermarine Walrus making a deck landing


We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

Supermarine Walrus making a deck landing

Here we see a Supermarine Walrus making a deck landing on a British aircraft carrier in the Far East


Tag Archives: Walri

In a recent blog post, I wrote about the most famous flying boat of World War Two, the Short Sunderland. I was lucky enough to visit the RAF Museum at Hendon in north London, where the aircraft is positioned in a very large space, unlike the way it was rather cramped way it was displayed when I went to Duxford in 2009:

With the Sunderland, under its starboard wing almost, is a Supermarine Walrus, which is not a flying boat but an amphibian, an aircraft which can go on land as well as on water.

The Walrus is an extremely unattractive flying machine, and it is extremely difficult to imagine that it was designed by RJ Mitchell, the man who designed the world’s most beautiful aircraft ever. This was the fighter that was originally to be called the Supermarine Shrew, until the name was changed to Supermarine Spitfire (“just the sort of bloody silly name they would choose.” (Mitchell)).

The Walrus was intended to be a gunnery spotting aircraft for sea battles between big warships, but this only happened twice, in the Battle of Cape Spartivento and the Battle of Cape Matapan. In actual fact, the Walrus’ main task was to patrol the seas looking for German or Italian submarines and surface warships. By 1941, the Walruses, or perhaps Walri, had air-to-surface radar for this purpose, although by 1943, all catapult-launched aircraft on Royal Navy ships, including the Walrus, were being phased out as the catapult and the hangar took up too much deck space.

The Walrus was then used at sea only on aircraft carriers as its landing speed was very low and neither flaps nor a tail-hook was necessary. The Royal Navy didn’t have that many aircraft carriers, so the main use of the Walrus now became chiefly air-sea rescue from land bases.

Before the Walrus, the British had not had any aircraft specifically designed for air-sea rescue in home waters.

Here’s the Walrus from the front:

And here it is from the back. Notice how the four bladed propeller is so close to the rear gunner that it may give him a short-back-and-sides haircut if he is not careful:

Here are the wheels which the pilot would lower before landing in the normal way on a runway. As I mentioned above, the Walrus had such a low stalling speed that it could land on an aircraft carrier without recourse to an arrester hook or to any safety nets. Presumably this allowed the Walrus to transport very badly wounded casualties to an aircraft carrier for immediate medical treatment, if the wounded man was too badly injured for a long flight to land :

Here are the floats underneath each wing tip. They appear to have about three thousand of Rosie the Riveter’s finest holding them together:

And to finish up, here’s an overall view of a Walrus:

It flies at about 55mph, but finds long climbs rather challenging. No, just joking!


Supermarine Aviation Works – Walrus

courtesy of https://en.wikipedia.org/wiki/Supermarine_Walrus
The Supermarine Walrus was a British single-engine amphibious biplane reconnaissance aircraft designed by R. J. Mitchell and first flown in 1933. It was operated by the Fleet Air Arm (FAA) and also served with the Royal Air Force (RAF), Royal Australian Air Force (RAAF), Royal Canadian Air Force (RCAF), Royal New Zealand Navy (RNZN) and Royal New Zealand Air Force (RNZAF). It was the first British squadron-service aircraft to incorporate a fully retractable main undercarriage, completely enclosed crew accommodation, and an all-metal fuselage.

Designed for use as a fleet spotter to be catapult launched from cruisers or battleships, the Walrus was later employed in a variety of other roles, most notably as a rescue aircraft for downed aircrew. It continued in service throughout the Second World War.

Development
Supermarine Walrus I, serial number K5783, from the first production batch. Photo taken between 1937 and 1939.

The Walrus was initially developed as a private venture in response to a 1929 Royal Australian Air Force (RAAF) requirement for an aircraft to be catapult-launched from cruisers, and was originally called the Seagull V, although it only resembled the earlier Supermarine Seagull III in general layout. Construction was started in 1930 but owing to Supermarine’s other commitments it was not completed until 1933. The single-step hull was constructed from aluminium alloy, with stainless-steel forgings for the catapult spools and mountings. Metal construction was used because experience had shown that wooden structures deteriorated rapidly under tropical conditions.

The wings, which were slightly swept back, had stainless-steel spars and wooden ribs and were covered in fabric.

The lower wings were set in the shoulder position with a stabilising float mounted under each one. The horizontal tail-surfaces were positioned high on the tail-fin and braced on either side by N stuts. The wings could be folded on ship, giving a stowage width of 17 feet 6 inches (5.33 m). The single 620 hp (460 kW) Pegasus II M2 radial engine was housed at the rear of a nacelle mounted on four struts above the lower wing and braced by four shorter struts to the centre-section of the upper wing. This powered a four-bladed wooden propeller in pusher configuration. The engine nacelle contained the oil tank, arranged around the air intake at the front of the nacelle to act as an oil cooler, and electrical equipment and had a number of access panels for maintenance. A supplementary oil cooler was mounted on the starboard side.

Fuel was carried in two tanks in the upper wings.

The pusher configuration had the advantages of keeping the engine and propeller further out of the way of spray when operating on water and reducing the noise level inside the aircraft. Also, the moving propeller was safely away from any crew standing on the front deck, which would be done when picking up a mooring line.

The engine was offset by three degrees to starboard to counter any tendency of the aircraft to yaw due to unequal forces on the rudder caused by the vortex from the propeller. A solid aluminium tailwheel was enclosed within a small water-rudder, which could be coupled to the main rudder for taxying or disengaged for take-off and landing.

Although the aircraft typically flew with one pilot, there were positions for two. The left-hand position was the main one, with the instrument panel and a fixed seat, while the right-hand seat could be folded away to allow access to the nose gun-position via a crawl-way.

An unusual feature was that the control column was not a fixed fitting in the usual way, but could be unplugged from either of two sockets at floor level. It became a habit for only one column to be in use and when control was passed from the pilot to co-pilot or vice-versa, the control column would simply be unplugged and handed over. Behind the cockpit, there was a small cabin with work stations for the navigator and radio operator.

Armament usually consisted of two .303 in (7.7 mm) Vickers K machine guns, one in each of the open positions in the nose and rear fuselage with provision for carrying bombs or depth charges mounted beneath the lower wings. Like other flying boats, the Walrus carried marine equipment for use on the water, including an anchor, towing and mooring cables, drogues and a boat-hook.

The prototype was first flown by ‘Mutt’ Summers on 21 June 1933 five days later it made an appearance at the SBAC show at Hendon, where Summers startled the spectators (R. J. Mitchell among them) by looping the aircraft. Such aerobatics were possible because the aircraft had been stressed for catapult launching. On 29 July Supermarine handed the aircraft over to the Marine Aircraft Experimental Establishment at Felixstowe. Over the following months extensive trials were carried out, including shipborne trials aboard Repulse and Valiant carried out on behalf of the Royal Australian Navy and catapult trials carried out by the Royal Aircraft Establishment at Farnborough, becoming the first amphibious aircraft in the world to be launched by catapult with a full military load, piloted by Flight Lieutenant Sydney Richard Ubee.

The strength of the aircraft was demonstrated in 1935, when the prototype was attached to the battleship Nelson at Portland. With the commander-in-chief of the Home Fleet, Admiral Roger Backhouse, on board the pilot attempted a water touch-down, forgetting that the undercarriage was in the down position. The Walrus was immediately flipped over but the occupants only had minor injuries the machine was later repaired and returned to service. Soon afterwards, the Walrus became one of the first aircraft to be fitted with an undercarriage position indicator on the instrument panel.

Test pilot Alex Henshaw later stated that the Walrus was strong enough to make a wheels-up landing on grass without much damage (he also commented that it was “the noisiest, coldest and most uncomfortable” aircraft he had ever flown). When flying from a warship, the Walrus would be recovered by touching-down alongside, then lifted from the sea by a ship’s crane. The aircraft’s lifting-gear was kept in a compartment in the section of wing directly above the engine – one of the Walrus’ crew would climb onto the top wing and attach this to the crane hook. Landing and recovery was a straightforward procedure in calm waters, but could be very difficult if the conditions were rough. The usual procedure was for the parent ship to turn through around 20° just before the aircraft touched down, thus creating a ‘slick’ to the lee side of ship on which the Walrus could alight, this being followed by a fast taxi up to the ship before the ‘slick’ dissipated.

The RAAF ordered 24 examples of the Seagull V in 1933, these being delivered from 1935. These aircraft differed from the prototype and the aircraft flown by the RAF in having Handley-Page slots fitted to the upper wings. This was followed by the first order for 12 aircraft from the RAF, placed in May 1935 with the first production aircraft, serial number K5772, flying on 16 March 1936. In RAF service the type was named the Walrus. Initial production aircraft were powered by the Pegasus II M2: from 1937, the 750 hp (560 kW) Pegasus VI was fitted.
Production aircraft differed in minor details from the prototype. The transition between the upper decking and the aircraft sides was rounded off, the three struts bracing the tailplane were reduced to two, and the trailing edges of the lower wing were hinged to fold 90° upwards rather than 180° downwards when the wings were folded, and the external oil cooler was omitted.
A total of 740 Walruses were built in three major variants: the Seagull V, Walrus I, and the Walrus II. The Mark IIs were all constructed by Saunders-Roe and the prototype first flew in May 1940. This aircraft had a wooden hull, which was heavier but had the advantage of using less of the precious wartime stockpiles of light metal alloys. Saunders-Roe would go on to build under license 270 metal Mark Is and 191 wooden-hulled Mark IIs.

The successor to the Walrus was the Supermarine Sea Otter – a similar but more powerful design. Sea Otters never completely replaced the Walruses, and served alongside them in the air-sea rescue role during the latter part of the war. A post-war replacement for both aircraft, the Supermarine Seagull, was cancelled in 1952, with only prototypes being constructed. By that time, helicopters were taking over from small flying-boats in the air-sea rescue role. The Walrus was affectionately known as the “Shagbat” or sometimes “Steam-pigeon” the latter name coming from the steam produced by water striking the hot Pegasus engine.

Operational history
Walrus deliveries to the RAF started in 1936 when the first example to be deployed was assigned to the New Zealand division of the Royal Navy, on Achilles- one of the Leander-class light cruisers that carried one Walrus each. The Royal Navy Town-class cruisers carried two Walruses during the early part of the war and Walruses also equipped the York-class and County-class heavy cruisers. Some battleships, such as Warspite and Rodney carried Walruses, as did the monitor Terror and the seaplane tender Albatross.

By the start of World War II the Walrus was in widespread use. Although its principal intended use was gunnery spotting in naval actions, this only occurred twice: Walruses from Renown and Manchester were launched in the Battle of Cape Spartivento and a Walrus from Gloucester was used in the Battle of Cape Matapan.

The main task of ship-based aircraft was patrolling for Axis submarines and surface-raiders, and by March 1941, Walruses were being deployed with Air to Surface Vessel (ASV) radars to assist in this.

During the Norwegian Campaign and the East African Campaign, they also saw very limited use in bombing and strafing shore targets.
In August 1940, a Walrus operating from Hobart bombed and machine-gunned an Italian headquarters at Zeila in Somalia. By 1943, catapult-launched aircraft on cruisers and battleships were being phased out their role at sea was taken over by much improved radar. Also, a hangar and catapult occupied a considerable amount of valuable space on a warship. However, Walruses continued to fly from Royal Navy carriers for air-sea rescue and general communications tasks. Their low landing speed meant they could make a carrier landing despite having no flaps or tailhook.

Air-sea rescue
The specialist RAF air-sea rescue squadrons flew a variety of aircraft, using Spitfires and Boulton Paul Defiants to patrol for downed aircrew, Avro Ansons to drop supplies and dinghies, and Walruses to pick up aircrew from the water. RAF air-sea rescue squadrons were deployed to cover the waters around the United Kingdom, the Mediterranean Sea and the Bay of Bengal. Over a thousand aircrew were picked up during these operations, with 277 Squadron responsible for 598 of these.

Experimental use
In late 1939 two Walruses were used at Lee-on-Solent for trials of ASV (Air to Surface Vessel) radar, the dipole aerials being mounted on the forward interplane struts. In 1940 a Walrus was fitted with a forward-firing Oerlikon 20 mm cannon, intended as a counter-measure against German E-boats. Although the Walrus proved to be stable gun-platform, the muzzle flash rapidly blinded the pilot, and the idea was not taken up.

Other users
Three Walruses N.18 (N2301), N.19 (N2302) and N.20 (N2303) were to be delivered on 3 March 1939, and used by Irish Air Corps as maritime patrol aircraft during the Irish Emergency of World War II. They were scheduled to fly from Southampton to Baldonnel Aerodrome, Ireland. N.19 made the trip successfully, but N.20 had to be rerouted to Milford Haven and N.18 and its crew of two (LT Higgins and LT Quinlan) were left with no choice but to go down during high seas causing damage to the hull. N.18 ditched near Ballytrent, just south of the former United States Naval Air Station, Wexford. It was decided to tow the N.18, with help of the Rosslare Harbour lifeboat and a local fishing boat to the launch slip once used for the Curtiss H-16s during WW1. It was then loaded on a truck to complete its journey to the Baldonnel Aerodrome where it was repaired. The Supermarine Walrus N.18 (also identified as L2301) is currently on display at the Fleet Air Arm Museum in Yeovilton, England. N.18 (N2301) is the only one of the 3 aircraft to sustain the test of time.

A Walrus I was shipped to Arkhangelsk with other supplies brought on the British Convoy PQ 17. After sustaining damage, it was repaired and supplied to the 16th air transport detachment. This sole Walrus flew to the end of 1943.

After the war, some Walruses continued to see limited military use with the RAF and foreign navies. Eight were operated by Argentina, two flew from the cruiser ARA La Argentina as late as 1958. Other aircraft were used for training by the French Navy’s Aviation navale.

Civil use
Walruses also found civil and commercial use. They were briefly used by a whaling company, United Whalers. Operating in the Antarctic, they were launched from the factory ship FF Balaena, which had been equipped with an ex-navy aircraft catapult. A Dutch whaling company embarked Walruses, but never flew them. Four aircraft were bought from the RAAF by Amphibious Airways of Rabaul. Licensed to carry up to ten passengers, they were used for charter and air ambulance work, remaining in service until 1954.

Variants
Seagull V: Original Metal-hull version.
Walrus I: Metal-hull version.
Walrus II: Wooden-hull version.

References used

o Flypast Magazine
o The Internet

Aftermarket Extras:

o Eduard Interior Colour PE
o Eduard Exterior PE
o Eduard Brassin Wheel Set
o Montex Masks
o Rope from the Spares box


Operational history

The first Seagull V, A2-1, was handed over to the Royal Australian Air Force in 1935, with the last, A2-24 delivered in 1937. The type served aboard HMA Ships Australia, Canberra, Sydney, Perth and Hobart.

Walrus deliveries to the RAF started in 1936 when the first example to be deployed was assigned to the New Zealand division of the Royal Navy, on Achilles– one of the Leander-class light cruisers that carried one Walrus each. The Royal Navy Town-class cruisers carried two Walruses during the early part of the war and Walruses also equipped the York-class and County-class heavy cruisers. Some battleships, such as Warspite and Rodney carried Walruses, as did the monitor Terror and the seaplane tender Albatross.

By the start of World War II the Walrus was in widespread use. Although its principal intended use was gunnery spotting in naval actions, this only occurred twice: Walruses from Renown and Manchester were launched in the Battle of Cape Spartivento and a Walrus from Gloucester was used in the Battle of Cape Matapan. [18] The main task of ship-based aircraft was patrolling for Axis submarines and surface-raiders, [18] and by March 1941, Walruses were being deployed with Air to Surface Vessel (ASV) radars to assist in this. [19] During the Norwegian Campaign and the East African Campaign, they also saw very limited use in bombing and strafing shore targets. [20] In August 1940, a Walrus operating from Hobart bombed and machine-gunned an Italian headquarters at Zeila in Somalia. [21]

By 1943, catapult-launched aircraft on cruisers and battleships were being phased out their role at sea was taken over by much improved radar. Also, a hangar and catapult occupied a considerable amount of valuable space on a warship. However, Walruses continued to fly from Royal Navy carriers for air-sea rescue and general communications tasks. Their low landing speed meant they could make a carrier landing despite having no flaps or tailhook. [22]

Air-sea rescue

The Walrus was used in the air-sea rescue role in both the Royal Navy and the Royal Air Force. The specialist RAF Air Sea Rescue Service squadrons flew a variety of aircraft, using Spitfires and Boulton Paul Defiants to patrol for downed aircrew, Avro Ansons to drop supplies and dinghies, and Walruses to pick up aircrew from the water. [19] RAF air-sea rescue squadrons were deployed to cover the waters around the United Kingdom, the Mediterranean Sea and the Bay of Bengal. [23] Over a thousand aircrew were picked up during these operations, with 277 Squadron responsible for 598 of these. [24]

Experimental use

In late 1939 two Walruses were used at Lee-on-Solent for trials of ASV (Air to Surface Vessel) radar, the dipole aerials being mounted on the forward interplane struts. In 1940 a Walrus was fitted with a forward-firing Oerlikon 20 mm cannon, intended as a counter-measure against German E-boats. Although the Walrus proved to be a stable gun-platform, the muzzle flash rapidly blinded the pilot, and the idea was not taken up. [25]

Other users

Three Walruses N.18 (L2301), N.19 (L2302) and N.20 (L2303) were to be delivered on 3 March 1939, and used by Irish Air Corps as maritime patrol aircraft during the Irish Emergency of World War II. [23] They were scheduled to fly from Southampton to Baldonnel Aerodrome, Ireland. N.19 made the trip successfully, but N.20 had to be rerouted to Milford Haven and N.18 and its crew of two (LT Higgins and LT Quinlan) were left with no choice but to go down during high seas causing damage to the hull. N.18 ditched near Ballytrent, just south of the former United States Naval Air Station, Wexford. It was decided to tow the N.18, with help of the Rosslare Harbour lifeboat and a local fishing boat to the launch slip once used for the Curtiss H-16s during WW1. It was then loaded on a truck to complete its journey to the Baldonnel Aerodrome where it was repaired. The Supermarine Walrus N.18 (also identified as L2301) is currently on display at the Fleet Air Arm Museum in Yeovilton, England. N.18 (N2301) is the only one of the 3 aircraft to sustain the test of time.

A Walrus I was shipped to Arkhangelsk with other supplies brought on the British Convoy PQ 17. After sustaining damage it was repaired and supplied to the 16th air transport detachment. This sole Walrus flew to the end of 1943. [26]

After the war, some Walruses continued to see limited military use with the RAF and foreign navies. Eight were operated by Argentina, two flew from the cruiser ARA La Argentina as late as 1958. [27] Other aircraft were used for training by the French Navy's Aviation navale. [27]

Civil use

Walruses also found civil and commercial use. They were briefly used by a whaling company, United Whalers. Operating in the Antarctic, they were launched from the factory ship FF Balaena, which had been equipped with a surplus navy aircraft catapult. [27] The aircraft used were slightly modified they were fitted with electrical sockets to power the electrically heated suits, worn by the crew under their immersion suits. A small, petrol-burning cabin heater was fitted to help keep the crews comfortable during flights that could last over five hours. [28]

A Dutch whaling company embarked Walruses, but never flew them. [27] Four aircraft were bought from the RAAF by Amphibious Airways of Rabaul. Licensed to carry up to ten passengers, they were used for charter and air ambulance work, remaining in service until 1954. [29]


The process of building decks is not nearly the same today as it was a decade or more ago. While the outdoor environment and the range of design options have remained relatively constant, emerging technologies and new products require a deeper understanding of industry codes and best practices.

The list of materials that can be used to build decks has certainly grown, or in some cases changed significantly. There are new varieties of pressure-treated material, for example, that can affect the choice of fasteners. High-performance building designs that include a continuous layer of exterior insulation complicate the attachment of deck ledgers.

As a deck builder, inspector, and plans analyst, I have seen a lot of inferior deck-building practices from professionals and do-it-yourselfers alike. I’ve also seen an abundance of bad information that perpetuates problematic designs and poor construction practices. A badly built deck is not only more likely to fail, it’s also dangerous for those who use it.

Here, I highlight the most common errors I see in deck building and offer some suggestions to ensure that your next deck is safe and durable.

Mistake 1: Failing to install a continuous handrail on stairs

The post in the middle of this flight of stairs interrupts the top of the railing, which was designed to serve as the handrail. A new continuous handrail, albeit an unsightly one, had to be added.

The error: For construction or aesthetic purposes, builders regularly interrupt handrails with newel posts. It’s also common to see a guard’s top rail used as a handrail.

The solution: Code provision R311.7.8.2 requires that a continuous handrail be installed on any set of stairs that has four or more steps. A continuous guard free of midspan posts extending through the top can be used as a handrail, but only if it meets specific geometric requirements. To be considered a handrail, the guard’s top rail must be graspable by those walking up and down the stairs. If a post interrupts a guard’s top rail, a true handrail must be added to the guard running along the stairs.

Mistake 2: Installing hardware incorrectly and using the wrong fasteners

Always follow manufacturer guidelines for appropriate fastener types and sizes, and use stainless-steel or galvanized fasteners if you are using pressured-treated lumber.

The error: Incorrect fasteners in hangers are a notorious mistake. For example, deck screws are not a proper way to attach joist hangers, and using 1-1⁄4-in.-long 10d nails where 3-1⁄ 2-in. 16d nails are required is a sure sign that manufacturer instructions were not followed.

Fasteners that don’t have the correct corrosion-resistance rating will fail quickly when installed in treated lumber. Also, using only one-half of a two-part post-to-beam connector and installing under-size bolts in 6࡬ post bases are common installation errors

The solution: For hardware to work as the manufacturer claims it will and the way the inspector expects it to, follow the manufacturer’s installation instructions. Proprietary hardware is not specified in the code therefore, it is considered an alternative. Alternatives are approved via testing or engineering, and that information must be provided to the building official. The only way to be sure hardware will perform as expected is if it is installed as it was tested or designed. Beyond code compliance, valid product warranties depend on proper installation.

Mistake 3: Bolting beams to the sides of posts

The error: A tragedy brought to us from the aisles of big-box stores: directions to deck builders to bolt deck beams to the sides of support posts. The average backyard deck has relatively few posts. Fewer posts result in greater loads at beam connections. It would take a huge load to shear a 1⁄ 2-in.-dia. bolt, but long before that occurred, wood around the bolt could be crushed, potentially resulting in a failed connection.

The solution: Each ply of a multispan beam, whether

single or multi-ply, must have full bearing on intermediate

posts. This can be accomplished by notching a 6࡬

to accept a 2-ply beam and bolting the beam to it, or by

the use of an approved post cap. With all the hardware

available to handle various direct-bearing applications of different-size beams and posts, there is no excuse for

disregarding this code requirement.

Mistake 4: Over-spanning composite decking

To meet the span tolerance of this diagonally installed composite decking properly, additional joists and hangers had to be added to the existing deck framing.

The error: The maximum span of wood-and-plastic composite decking generally depends on the type of plastic used in the product. It’s important to follow the span limits of a specific product as outlined in the manufacturer’s installation instructions, which some builders fail to review. Over-spanning composite decking is most commonly a problem when deck boards are run diagonally over joists or when they’re used as stair treads.

The solution: Floor joists for a deck are typically installed at 16 in. on-center, which won’t properly support some composite-decking products when installed on an angle. In new construction, be sure floor joists are installed at the correct spacing. In existing decks, adding more floor joists is the only remedy. Similarly, additional stair stringers might have to be added to stairs where composite decking serves as the treads. Stair treads must be able to resist a concentrated load of 300 lb. over an area of 4 sq. in. This requirement puts a lot of pressure on the actual tread material to support concentrated loads. Some composite products are limited to an 8-in. maximum span when used as stair treads, which requires the support of six stringers in a 36-in.-wide stairway.

Mistake 5: Building stairs with incorrect riser heights

Once you have determined the rise and run of your stairs, stringer layout is straightforward. One detail, however, is easy to overlook. The bottom riser needs to be one tread thickness shorter than the rest.

The error: Often, the bottom step on a set of deck stairs is roughly 1 in. taller than the rest. Code allows a maximum variation of only 3⁄8 in. between riser heights. This guideline often confuses inexperienced carpenters, who insist that they cut every notch in the stringer the same.

The solution: Every notch cut into a stringer has an identical riser height except for the bottom one. The steps notched out of the stringer in the middle of the flight have treads placed above and below each step, effectively adding the same tread thickness to each riser height so that they remain constant. The bottom step doesn’t have a tread below it, though, so you must subtract the thickness of the tread from the height of the bottom riser, which is the bottom of the stringer.

Mistake 6: Ignoring clearances and inhibiting access

Some clearances around a deck are code-required, such as providing a minimum 36-in.-tall escape path from a basement egress window. Others are simply practical, such as ensuring access to hose bibs. Each clearance should be considered with equal diligence.

The error: Although well constructed, some decks are still code violations simply in how they interact with the house. For example, some stairs on multilevel decks end up near windows that the builder has not replaced with tempered-glass units. Other decks are built too close to the house’s main electrical service panel or the service conductors overhead—which need to be at least 10 ft. above a deck or 3 ft. to the side of a deck, according to code (E3604).

The solution: No matter what features exist on the exterior of a home—windows, air-conditioning compressors, low-hanging soffits, exterior lights, outdoor receptacle outlets, dryer vents—identify the required clearances before starting a deck design. While some features will influence the shape and location of the deck, other features may require only that appropriate access be integrated into the design of the deck.

Mistake 7: Attaching deck ledgers poorly

If sistering deck joists to floor joists isn’t an option, adding a beam, posts, and footings can help to relieve some of the stress placed on the fasteners connecting the ledger to the end grain of the cantilevered floor joists.

The error: The majority of deck plans end with a straight, continuous line at the ledger, rather than details as to what the ledger is connecting to. Unfortunately, the way a ledger attaches to a house is one of the most critical elements in deck construction, and many builders get it wrong. For example, they bolt ledgers straight to brick, stucco, or EIFS cladding. These practices violate the code. One of the more egregious ledger mistakes is connecting the ledger to a rim joist nailed to the end grain of cantilevered floor joists—those that support a kitchen bump-out, for example.

The solution: Detailing a ledger properly depends on the building type, the cladding material, and the site conditions. Of all the parts of a deck, the ledger can rarely be treated the same from job to job. Long before construction begins, considerations must be made as to, for example, whether stucco needs to be cut back with new weep screed installed or whether a few courses of lap siding need to be removed to bolt and flash the new ledger properly. Code requires that band joists supporting deck ledgers bear fully on the primary structure capable of supporting all required loads—in other words, they can’t be part of a cantilevered floor. A better option in that scenario is to build a freestanding deck that doesn’t rely on the cantilever to support it.

When set above an area’s frost line, footings can heave.

Mistake 8: Setting piers in disturbed soil

The error: When it comes to digging footings for deck piers, some builders are lazy. To avoid deck ledger failures, freestanding decks are becoming popular. But the piers nearest the foundation may be set atop backfill. In areas where the frost depth is not an issue and precast foundation blocks are used, they’re often set on top of the exposed grade — a code violation.

The solution: Foundation systems are required to extend a minimum of 12 in. into undisturbed soil (R403.1.4). In cold climates, where the ground freezes in winter, a pier foundations for non-freestanding decks must extend to a depth below that which is likley to freeze—in some places deeper than 48 in. This prevents the soil below the pier from freezing and heaving the pier upward

Piers must bear on undisturbed soil as well as set below the frost line. This could mean the need for 3-ft.-deep footings in some areas. However, if the piers are in a backfill region, as is the case with piers nearest the house on a freestanding deck, the footing depth may have to be as deep as 10 ft. to reach undisturbed soil and to comply with code.

Precast foundation blocks must be set at least 12 in. into the ground. However, even in the middle of a lot, the topsoil is tilled roughly 6 in. prior to seeding, so it’s likely that the footing needs to be at least 18 in. deep to comply with code. Assume that all deck piers and foundation blocks require some digging.

Mistake 9: Incorrectly attaching guard posts

The error: Connecting a guard post to a deck incorrectly is among the most dangerous deck-building errors. Fastening guard posts to deck rim joists or floor joists with wood screws is not acceptable. While some builders get the guard-post-to-rim-joist connection right, they don’t always make sure that the rim joist is attached to the deck framing properly.

The solution: The code (table R301.5) requires the top of a guard to be capable of resisting a concentrated load of 200 lb. in any direction. Depending on the design of the guard assembly, a stout guard-post-to-deck connection can be accomplished with blocking and through-bolts or with horizontally oriented hold-down hardware. In some rail designs, most of the load resistance is handled by the post connection to the deck. In those instances, the post should be attached to the joists, not the rim, because the rim is not usually fastened to the joists in a manner capable of transferring the load. Rims are typically nailed into the ends of the joists, the weakest possible connection for withdrawal resistance.

There’s more to consider than just the post-to-deck connection. The assembly must be able to resist a concentrated load at any point along the top of the rail. Posts are typically spaced 5 ft. to 6 ft. apart. When a continuous top cap runs across the posts, it acts like a horizontal beam to help distribute the load over a larger area. When the top of the guardrail is interrupted by a post that runs long, however, there is a considerable increase in the leverage the post puts on its connections.

Beams suffer the greatest amount of deflection at the center of their post-to-post span. Therefore, strong beams are spliced atop posts. If you can’t stagger splices over different posts, then placing them over a single post is permissible.

Mistake 10: Making beam splices in the wrong places

The error: When a long built-up beam spans multiple posts, many builders run one 2x long so it extends beyond the supporting post. They apparently believe this practice is good because splices of opposing beam plies are separated rather than being only inches apart on top of a post. Unfortunately in these cases, an engineer’s evaluation or a rebuild of the beam is required.

The solution: Beams are under two stresses: bending and shear. Shear forces act perpendicular to the length of the beam and are greatest near the bearing ends.

Bending changes the beam’s shape, a force called deflection, and is greatest in the center of the beam span. The code lists maximum allowable limits for deflection. In deck beams, the deflection limit is typically reached long before shear limits are a consideration. Any reduction in bending resistance also increases deflection potential, which could lead to a code noncompliance.

Beam splices that miss the bearing point by a small amount don’t greatly affect bending or deflection, and the shear strength of one fewer ply is likely still sufficient. In these cases, the cost of an engineer’s review might just get you the OK to build. But don’t put splices in the center of a span — build the beam so that splices land on top of supporting posts.

More on Decks:

Ultimate Deck Build – In this video, Fine Homebuilding’s Justin Fink gives an introduction on how the deck will be built. This Ultimate Deck Build series includes step-by-step instructions on how to build a better deck

Is Your Deck Safe? – Protect yourself from collapse, rot, and nasty splinters. Inspect these eight critical areas every season.

How to Build a Deck: Video Series – These four videos demonstrate the entire process, from planning to staining.

First Aid for a Failing Deck – The life span of most residential decks is 20 years or less. In this article, veteran carpenter Rick Arnold tunes up an existing deck. He removes the old decking and railing, saving the original deck frame while taking steps to safeguard users from a future deck collapse.

For more photos, drawings, and details, click the View PDF button below.

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.


Supermarine Walrus

new

Diarist
Administrator

Post by Diarist on Sept 21, 2015 20:54:20 GMT 1

The Supermarine Walrus is a British single-engine amphibious biplane reconnaissance aircraft designed by R. J. Mitchell and first flown on 21 June 1933. It is the first British squadron-service aircraft to incorporate a fully retractable main undercarriage, completely enclosed crew accommodation, and an all-metal fuselage.

The Walrus was initially developed as a private venture in response to a 1929 Royal Australian Air Force (RAAF) requirement for an aircraft to be catapult-launched from cruisers, and was originally called the Seagull V, although it only resembled the earlier Supermarine Seagull III in general layout. Construction was started in 1930 but owing to Supermarine's other commitments it was not completed until 1933.

The single-step hull was constructed from aluminium alloy, with stainless-steel forgings for the catapult spools and mountings. Metal construction is used because experience had shown that wooden structures deteriorated rapidly under tropical conditions. The wings, which are slightly swept back, has stainless–steel spars and wooden ribs and are covered in fabric. The lower wings are set in the shoulder position with a stabilising float mounted under each one. The horizontal tail-surfaces were positioned high on the tail-fin and braced on either side by N stuts. The wings could be folded on ship, giving a stowage width of 17 feet 6 inches (5.33 m). The single 620 hp (460 kW) Pegasus II M2 radial engine is housed at the rear of a nacelle mounted on four struts above the lower wing and braced by four shorter struts to the centre-section of the upper wing. This powers a four-bladed wooden propeller in pusher configuration. The engine nacelle contains the oil tank, arranged around the air intake at the front of the nacelle to act as an oil cooler, and electrical equipment and has a number of access panels for maintenance. A supplementary oil cooler is mounted on the starboard side. Fuel is carried in two tanks in the upper wings. The pusher configuration has the advantages of keeping the engine and propeller further out of the way of spray when operating on water and reducing the noise level inside the aircraft. Also, the moving propeller is safely away from any crew standing on the front deck, which would be done when picking up a mooring line. The engine is offset by three degrees to starboard to counter any tendency of the aircraft to yaw due to unequal forces on the rudder caused by the vortex from the propeller.

A solid aluminium tail-wheel is enclosed within a small water-rudder, which can be coupled to the main rudder for taxying or disengaged for take-off and landing.

Although the aircraft typically can fly with one pilot, there are positions for two. The left-hand position is the main one, with the instrument panel and a fixed seat, while the right-hand seat can be folded away to allow access to the nose gun-position via a crawl-way. An unusual feature is that the control column was not a fixed fitting in the usual way, but can be unplugged from either of two sockets at floor level. It has become a habit for only one column to be in use and when control is passed from the pilot to co-pilot or vice versa, the control column can simply be unplugged and handed over. Behind the cockpit, there is a small cabin with work stations for the navigator and radio operator.

Armament usually consists of two .303 in (7.7 mm) Vickers K machine guns, one in each of the open positions in the nose and rear fuselage with provision for carrying bombs or depth charges mounted beneath the lower wings. Like other flying boats, the Walrus carries marine equipment for use on the water, including an anchor, towing and mooring cables, drogues and a boat-hook.

The prototype was first flown by "Mutt" Summers on 21 June 1933 five days later it made an appearance at the SBAC show at Hendon, where Summers startled the spectators (R. J. Mitchell among them) by looping the aircraft. Such aerobatics were possible because the aircraft had been stressed for catapult launching. On 29 July Supermarine handed the aircraft over to the Marine Aircraft Experimental Establishment at Felixstowe. Extensive trials are to be carried out, including shipborne trials aboard HMS Repulse and HMS Valianton behalf of the Royal Australian Navy and catapult trials carried out by the Royal Aircraft Establishment at Farnborough, becoming the first amphibious aircraft in the world to be launched by catapult with a full military load.


Scimitar vs. Other late 1957s fighters

I've always liked the Supermarine Scimitar. When it entered service in 1957 it joined the field populated by the MiG-19, Super Mystère, Saab 32 Lansen, F3H Demon, F-8 Crusader and others. I know the Scimitar suffered from poor area rule design, but overall was it a competitive aircraft for 1957?

Of course in a few short years (months?) the MiG-21, Phantom II, Mirage III will enter service, making the Scimitar much less competitive.

Mar 04, 2012 #2 2012-03-04T23:15

Scimitar had a poor deck landing history / loss rate I have read. Easy enough to check online:

". Overall the Scimitar suffered from a high loss rate 39 were lost in a number of accidents, amounting to 51% of the Scimitar's total production run. "

Mar 04, 2012 #3 2012-03-04T23:46

Yes, but that doesn't necessarily make it a poor fighter. I too have read the wiki article, but it doesn't say "why" the Scimitar had a poor deck landing history.

For example, this Scimitar was lost due to arrestor cable failure http://www.criticalpast.c. rrier_rescuing-the-pilot

However, this does not bode well http://www.ejection-histo. aft_by_Type/Scimitar.htm with a lot of losses to hydraulic failure. I have read that the Scimitar did leak a lot of fluid on the ground. Reminds me of my 1969 Triumph Tiger motorcycle.

So, assuming the hydraulics could be sealed properly, is the Scimitar any good?

Mar 05, 2012 #4 2012-03-05T01:31

Mar 05, 2012 #5 2012-03-05T03:03

Mar 05, 2012 #6 2012-03-05T03:19

Half of the Scimitars were lost in peace time due to operational mishaps. Do you seriously think things would have improved in a war?

No radar. In bad weather and at night, it was blind. In VMC during the day even the F-8 was going to have the advantage of situational awareness. IIRC, the Farmer E had a very basic radar for all weather intercepts. These were mostly gone from Soviet front line units by the time I entered the service, but I think the Cubans had them and I know the North Vietnamese had them. The F-4 always had superior radar range. However, in Viet Nam, the Farmer E was no slouch given our rules of engagement that required positive visual identification. The Scimitar was a slouch even with our rules of engagement.

Mar 05, 2012 #7 2012-03-05T10:51

I'd take a Grumman F11F Tiger over the Scimitar for day fighter duties.

It was more reliable and had better carrier characteristics, even though it didn't have a radar either (it was supposed to get the AN/APS-50, hence the longer nose of the last 157 of the 199 built).

It entered service in March 1957, but it was withdrawn from service starting in 1959 and finishing in 1961.

However, in 1957, the Vought F-8 didn't have much of a radar either. the F-8A also entered service in March 1957, and had only an AN/APG-30 ranging radar.

The F-8B, which began deliveries at the end of 1957, was the first Crusader with a "quite limited" all-weather capability, thanks to the AN/APS-67 scanning radar. The F-8C (delivered from January 1959) kept this radar, but added several improvements, including an up-rated engine.

The F-8D, delivered from June 1960, was the first "night rated" Crusader, with the AN/APQ-83/84 radar (retrofitted to F-8Cs in the early 1960s).


For a supersonic radar-equipped fighter in 1957 I'd take the Convair F-102, which entered service in April 1956.


Specifications (Supermarine Walrus I)

Data fromSupermarine aircraft since 1914, [42] Supermarine Walrus I & Seagull V Variants [43]

General characteristics

  • Crew: 4
  • Length: 37   ft 7   in (11.46   m) on wheels
  • Wingspan: 45   ft 10   in (13.97   m)
  • Height: 15   ft 3   in (4.65   m) on wheels
  • Wing area: 610   sq   ft (57   m 2 )
  • Empty weight: 4,900   lb (2,223   kg)
  • Gross weight: 7,200   lb (3,266   kg)
  • Max takeoff weight: 8,050   lb (3,651   kg)
  • Powerplant: 1 × Bristol Pegasus VI 9-cylinder air-cooled radial piston engine, 750   hp (560   kW)
  • Propellers: 4-bladed wooden fixed-pitch pusher propeller
  • Maximum speed: 135   mph (217   km/h, 117   kn) at 4,750   ft (1,448   m)
  • Cruise speed: 92   mph (148   km/h, 80   kn) * Alighting speed: 57   mph (50   kn 92   km/h)
  • Range: 600   mi (970   km, 520   nmi) at cruise
  • Service ceiling: 18,500   ft (5,600   m)
  • Rate of climb: 1,050   ft/min (5.3   m/s)
  • Time to altitude: 10,000   ft (3,000   m) in 12 minutes 30 seconds
  • Wing loading: 11.8   lb/sq   ft (58   kg/m 2 )
  • Power/mass: 0.094   hp/lb (0.155   kW/kg)
  • Guns: 2× .303   in (7.7   mm) Vickers K machine guns (one in nose, one behind wings)
  • Bombs: 6x 100   lb (45   kg) bombs

Supermarine Walrus K8541

HMS Leander was commissioned into service with the NZ Division of the Royal Navy and arrived in New Zealand in 1937. Once in New Zealand she undertook a tour of the nation’s ports. On 24 November 1937 at Wellington her Supermarine Walrus aircraft K8541 overturned in Wellington Harbour on landing because the pilot forgot to raise the wheels. The crew survived but the aircraft was written off.[1]

Leander’s aircraft was replaced by K8558 which remained in service until the aircraft were landed and not used again in mid 1942. Achilles landed its aircraft in 1939 before the war broke out. This aircraft was assigned to FAA 720 Catapult Squadron up until to 21 January 1940 and from then to 1944 700 Squadron.[2]

Colour Scheme and Markings

In 1937, the aircraft was painted silver with the RAF roundel on the fuselage and under the lower wings and on top of the upper wings and the plane number in black next to the roundel on the fuselage.

When K8558 was initially in service she was painted silver with the roundels. One the nose she also carried the ship’s badge of Leander. Underneath the cockpit was the code Z3. IN 1939, the plane was given the code P9A to show she was part of 720 Squadron. In her later service with 700 Squadron, the code markings were removed and FAA standard camouflage scheme of dark sea grey, dark slate grey and sky grey lower surfaces was applied. Aircraft number was in white, no code numbers were applied.[3]

Technical Specifications:[4]

Role: Spotter-reconnaissance amphibian for carrier-borne or catapult duties

Construction: Metal hull, fabric covered composite metal and wood wings

Engine: One 775hp Bristol Pegasus II M2 or VI

Dimensions: Span 45’10”, 17’11” folded

Weight: 4900lb empty, 8050 fully loaded

Performance: Maximum speed 135mph at 4750ft

Climb 5.5 minutes to 15,000ft

1 x Vickers K machinegun in bows and 1 or 2 machineguns amidships

Six 100lb or 2 x 250lb bombs or 2 Mk. VIII depth charges

Bibliography:

Darby, Charles, RNZAF: The First Decade 1937-1946, Melbourne: Kookaburra Technical Publications, 1978, pp. 18-19.

Thetford, Owen, British Naval Aircraft 1912-58, London: Putnam, 1958, pp. 291-295.

[1] Charles Darby, RNZAF: The First Decade 1937-1946, Melbourne: Kookaburra Technical Publications, 1978, p. 18.

[3] Charles Darby, RNZAF: The First Decade 1937-1946, Melbourne: Kookaburra Technical Publications, 1978, pp. 18-19.

[4] Owen Thetford, British Naval Aircraft 1912-58, London: Putnam, 1958, pp. 293-294.


Supermarine Walrus Mk.I – Part 2

Modelling work on the Supermarine Walrus Mk.I is now complete! This took a lot longer than intended – as ever, real life gets in the way. I have gone into far more detail than is necessary for this, but I figured that if I was going to make this thing, I may as well do a thorough job with it. Internal detailing is mostly rudimentary, but fairly well developed where visible from outside, like the cockpit.

Cockpit

Talking of the cockpit – this seems like as good a place as any to pick up from Part 1. There are two or three preserved Walruses around the world, so references for much of the interior is actually fairly abundant.

I haven’t included everything, and I’m sure I’ve made a few mistakes here and there. Some of the dials are from the Spitfire rather than the Walrus – they were the closest match I could find hopefully the same manufacturer means they weren’t too dissimilar! But given this whole plane is meant to be a simple deck asset for my King George V class battleships, this is more than good enough!

Hatches

The Walrus has a hatch in the nose/bow, and another in the aft fuselage. These hatches were used during various operations such as mooring, sea rescues, etc – and also for defensive purposes. Both hatches feature a machine gun track mount, to which a Vickers K machine gun can be fitted.

The forward hatch is a fairly circular plate, hinged across the centre and retained from inside. This would simply be removed and stowed inside the aircraft when it needed to be opened. The aft hatch is a much more elaborate affair, with glazing and the ability to slide forward out of the way.

I chose not to detail the forward hatch in any way (although the internals are present). For the rear hatch, I modelled everything I could see. I rigged this hatch, so I can easily control its position and configuration for ease of posing.

I completed the forward landing gear in Part 1, but left the tailwheel for later. Earlier Walruses did not have a true tail wheel fitted. Instead, there was a robust water rudder, intended to act as a simple skid when landing on a landing strip. A small metal wheel was inserted into this skid in order to protect the flight decks of aircraft carriers.

Later versions of the aircraft had fully-fledged pneumatic-tyred tailwheels. A good example of this can be seen on HD874, preserved at the Royal Australian Air Force museum, near Melbourne. Most in Fleet Air Arm service during the war appear to have been of the earlier type. Importantly, this includes those carried by the KGVs, so that is what I have modelled here.

Other details added in include the tail plane struts and various other small details. The rudder, elevators and tailwheel/water rudder are all fully rigged, and controlled by sliders for easy posing.

Bristol Pegasus Engine

Easily the most significant bit of work in Part 2 is the Bristol Pegasus 9-cylinder radial engine. This proved to be a small project all on it’s own, but the detail in them makes it worthwhile in my opinion! There are a fair few examples of this engine in various museums, so references were not too hard to come by.

Bristol Pegasus radial engine

I did not model the rear of the engine properly, since it will not be visible inside the nacelle pod that houses it. Materials (as with the rest of the plane) are rough placeholders for now.

Finishing up

There are of course numerous small details scattered all over the plane, from the bombs carried under each wing (fitted here are a pair of depth charges for anti-submarine operations, and four practice bombs on each wing).

Various eyebolts, shackles, ropes and even mooring bollards on the nose finish off the flying boat look. The Supermarine Walrus may not have the sexy looks of the Spitfire, but there is a certain appeal about her all the same (or I’ve been looking at it for too long!)

The next stage will be unwrapping everything and getting the materials sorted out. There were a few camouflage schemes employed on the Walruses as carried by the various ships of the KGV class, but I shall most likely limit it to just two variations. I’m rather tired of this subject at the moment though, so I will work on something completely different before I get all that done. Hopefully it won’t be another year before I update this again though!


Watch the video: Vaccines, Submarines and the Mountains. Episode 108 (July 2022).


Comments:

  1. Onslow

    I personally did not like it !!!!!

  2. Anakin

    I congratulate you, your thought will be useful

  3. Shakatilar

    Bravo, this brilliant phrase will come in handy



Write a message