Saturday, December 17, 2016
In 1802, Trevithick built one of his high-pressure steam engines to drive a hammer at the Pen-y-Darren Ironworks in Merthyr Tydfil, Mid Glamorgan . With the assistance of Rees Jones, an employee of the iron works and under the supervision of Samuel Homfray, the proprietor, he mounted the engine on wheels and turned it into a locomotive. In 1803, Trevithick sold the patents for his locomotives to Samuel Homfray.
Homfray was so impressed with Trevithick's locomotive that he made a bet with another ironmaster, Richard Crawshay, for 500 guineas that Trevithick's steam locomotive could haul ten tons of iron along the Merthyr Tydfil Tramroad from Penydarren ( ) to Abercynon ( ), a distance of 9.75 miles (16 km). Amid great interest from the public, on 21 February 1804 it successfully carried 10 tons of iron, 5 wagons and 70 men the full distance in 4 hours and 5 minutes, an average speed of approximately 2.4 mph (3.9 km/h). As well as Homfray, Crawshay and the passengers, other witnesses included Mr. Giddy, a respected patron of Trevithick and an 'engineer from the Government'. The engineer from the government was probably a safety inspector and particularly interested in the boiler's ability to withstand high steam pressures.
The configuration of the Pen-y-darren engine differed from the Coalbrookdale engine. The cylinder was moved to the other end of the boiler so that the firedoor was out of the way of the moving parts. This obviously also involved putting the crankshaft at the chimney end. The locomotive comprised a boiler with a single return flue mounted on a four wheel frame. At one end, a single cylinder with very long stroke was mounted partly in the boiler, and a piston rod crosshead ran out along a slidebar, an arrangement that looked like a giant trombone. As there was only one cylinder, this was coupled to a large flywheel mounted on one side. The rotational inertia of the flywheel would even out the movement that was transmitted to a central cog-wheel that was, in turn connected to the driving wheels. It used a high-pressure cylinder without a condenser, the exhaust steam was sent up the chimney assisting the draught through the fire, increasing efficiency even more.
The bet was won. Despite many people's doubts, it had been shown that, provided that the gradient was sufficiently gentle, it was possible to successfully haul heavy carriages along a "smooth" iron road using the adhesive weight alone of a suitably heavy and powerful steam locomotive. Trevithick's was probably the first to do so; however some of the short cast iron plates of the tramroad broke under the locomotive as they were intended only to support the lighter axle load of horse-drawn wagons and so the tramroad returned to horse power after the initial test run.
Homfray was pleased he won his bet. The engine was placed on blocks and reverted to its original stationary job of driving hammers.
In modern Merthyr Tydfil, behind the monument to Trevithick's locomotive is a stone wall, the sole remainder of the former boundary wall of Homfray's Penydarren House.
A full-scale working reconstruction of the Pen-y-darren locomotive was commissioned in 1981 and delivered to the Welsh Industrial and Maritime Museum in Cardiff; when that closed, it was moved to the National Waterfront Museum in Swansea. Several times a year it is run on a 40m length of rail outside the museum.
Friday, December 9, 2016
The Saturn V consisted of three stages—the S-IC first stage, S-II second stage and the S-IVB third stage—and the instrument unit. All three stages used liquid oxygen (LOX) as an oxidizer. The first stage used RP-1 for fuel, while the second and third stages used liquid hydrogen (LH2). The upper stages also used small solid-fueled ullage motors that helped to separate the stages during the launch, and to ensure that the liquid propellants were in a proper position to be drawn into the pumps.
The S-IVB (sometimes S4b, always pronounced "ess four bee") was built by the Douglas Aircraft Company and served as the third stage on the Saturn V and second stage on the Saturn IB. It had one J-2 engine. For lunar missions it was fired twice: first for the orbit insertion after second stage cutoff, and then for translunar injection (TLI).
The S-IVB evolved from the upper stage of the Saturn I rocket, the S-IV, and was the first stage of the Saturn V to be designed. The S-IV used a cluster of six engines but used the same fuels as the S-IVB — liquid hydrogen and liquid oxygen. It was also originally meant to be the fourth stage of a planned rocket called the C-4, hence the name S-IV.
Eleven companies submitted proposals for being the lead contractor on the stage by the deadline of 29 February 1960. NASA administrator T. Keith Glennan decided on 19 April that Douglas Aircraft Company would be awarded the contract. Convair had come a close second but Glennan did not want to monopolize the liquid hydrogen-fueled rocket market as Convair was already building the Centaur rocket stage.
In the end the Marshall Space Flight Center decided to use the C-5 rocket (later called the Saturn V), which had three stages and would be topped with an uprated S-IV called the S-IVB which instead of using a cluster of engines would have a single J-2 engine. Douglas was awarded the contract for the S-IVB because of the similarities between it and the S-IV. At the same time it was decided to create the C-IB rocket (Saturn IB) that would also use the S-IVB as its second stage and could be used for testing the Apollo spacecraft in Earth orbit.
Douglas built two distinct versions of the S-IVB, the 200 series and the 500 series. The 200 series was used by the Saturn IB and differed from the 500 in the fact that it did not have a flared interstage and had less helium pressurization on board as it would not be restarted. On the 500 series, the interstage needed to flare out to match the larger diameter of the S-IC and S-II stages of the Saturn V. The 200 series also had three solid rockets for separating the S-IVB stage from the S-IB stage during launch. On the 500 series this was reduced to two, and additional linear APS thrusters were added for ullage operations prior to restarting the J-2 engine.
Attitude control was provided by 2 Auxiliary Propulsion System pods, and by engine gimballing. The APS modules provided 150 pounds of thrust each, and were fuelled by a hypergolic mixture of dinitrogen tetroxide and monomethyl hydrazine. They were used for three-axis control during coast phases, roll control during J-2 firings, and (on the 500 series) ullage for the second ignition of the J-2 engine and deorbit into the moon.
A surplus S-IVB tank, serial number 212, was converted into the hull for Skylab, the United States' first space station. Skylab was launched on a Saturn V on May 14, 1973, and re-entered the atmosphere on July 11, 1979. A second S-IVB, serial number 515, was also converted into a backup Skylab, which never flew.
During Apollo 13, Apollo 14, Apollo 15, Apollo 16 and Apollo 17, the S-IVB stages were crashed into the Moon to perform seismic measurements used for characterizing the lunar interior.
Tuesday, December 6, 2016
Many thanks to my readers. I wouldn't have gotten this far without your readership.
Some of you may have noticed that I no longer publish in large amounts as I use d to.
This is because back in those days I was playing catchup, publishing models That I had already built before I started this blog.
Now That I'm all caught up, I only publish one to three models a month.
So no I'm not the speed demon some may have thought.
So on that note, a big hardy thankyoumuchly, and here's to many more years to come of The Great Canadian Model Builder's Web Page!!
Sunday, December 4, 2016
This aircraft served with 46 Squadron, Pilot Lt A.S. Lee, July - August 1917.
The Sopwith Pup was a British single-seater biplane fighter aircraft built by the Sopwith Aviation Company. It entered service with the Royal Flying Corps and the Royal Naval Air Service in the autumn of 1916. With pleasant flying characteristics and good manoeuvrability, the aircraft proved very successful. The Pup was eventually outclassed by newer German fighters, but it was not completely replaced on the Western Front until the end of 1917. Remaining Pups were relegated to Home Defence and training units. The Pup's docile flying characteristics also made it ideal for use in aircraft carrier deck landing and takeoff experiments.
In 1915, Sopwith produced a personal aircraft for the company's test pilot Harry Hawker, a single-seat, tractor biplane powered by a 50 hp Gnome rotary engine. This became known as Hawker's Runabout; another four similar aircraft have been tentatively identified as Sopwith Sparrows. Sopwith next developed a larger fighter that was heavily influenced by this design, though more powerful and controlled laterally with ailerons rather than by wing warping.
The resulting aircraft was a single-bay, single-seat biplane with a fabric-covered, wooden framework and staggered, equal-span wings. The cross-axle type main landing gear was supported by V-struts attached to the lower fuselage longerons. The prototype and most production Pups were powered by the 80 hp (60 kW) Le Rhône 9C rotary engine. Armament was a single 0.303 inch (7.7 mm) Vickers machine gun synchronized with the Sopwith-Kauper synchronizer.
A prototype was completed in February 1916 and sent to Upavon for testing in late March. The Royal Naval Air Service (RNAS) quickly ordered two more prototypes, then placed a production order. Sopwith was heavily engaged in production of the 1½ Strutter, and produced only a small number of Pups for the RNAS. Deliveries commenced in August 1916.
The Royal Flying Corps (RFC) also placed large orders for Pups. The RFC orders were undertaken by sub-contractors Standard Motor Co. and Whitehead Aircraft. Deliveries did not commence until the beginning of 1917. A total of 1,770 Pups were built by Sopwith (96), Standard Motor Co. (850), Whitehead Aircraft (820), and William Beardmore & Co. (30).
In May 1916, the RNAS received its first Pups for operational trials with "A" Naval Squadron. The first Pups reached the Western Front in October 1916 with No. 8 Squadron RNAS, and proved successful, with the squadron's Pups claiming 20 enemy machines destroyed in operations over the Somme battlefield by the end of the year. The first RFC Squadron to re-equip with the Pup was No. 54 Squadron, which arrived in France in December. The Pup quickly proved its superiority over the early Fokker, Halberstadt and Albatros biplanes. After encountering the Pup in combat, Manfred von Richthofen said, "We saw at once that the enemy aeroplane was superior to ours."
The Pup's light weight and generous wing area gave it a good rate of climb. Agility was enhanced by installing ailerons on both wings. The Pup had half the horsepower and armament of the German Albatros D.III, but was much more manoeuvrable, especially over 15,000 ft (4,500 m) due to its low wing loading. Ace James McCudden stated that "When it came to manoeuvring, the Sopwith [Pup] would turn twice to an Albatros' once ... it was a remarkably fine machine for general all-round flying. It was so extremely light and well surfaced that after a little practice one could almost land it on a tennis court." However, the Pup was also longitudinally unstable.
At the peak of its operational deployment, the Pup equipped only four RNAS squadrons (Nos. 3, 4, 8 and 9), and three RFC squadrons (Nos. 54, 46 and 66). By the spring of 1917, the Pup had been outclassed by the newest German fighters. The RNAS replaced their Pups, first with Sopwith Triplanes, and then with Sopwith Camels. The RFC soldiered on with Pups, in spite of increasing casualties, until it was possible to replace them with Camels in December 1917.
The raids on London by Gotha bombers in mid-1917 caused far more damage and casualties than the earlier airship raids. The ineffective response by British interceptor units had serious political repercussions. In response, No. 66 Squadron was withdrawn to Calais for a short period, and No. 46 was transferred for several weeks to Sutton's Farm airfield near London. Two new Pup squadrons were formed specifically for Home Defence duties, No. 112 in July, and No. 61 in August.
The first Pups delivered to Home Defence units utilised the 80 hp Le Rhône, but subsequent Home Defence Pups standardised on the more powerful 100 hp Gnome Monosoupape, which provided improved rate of climb. These aircraft were distinguishable by the addition of vents in the cowling face.
Sopwith Pups were also used in many pioneering carrier experiments. On 2 August 1917, a Pup flown by Sqn Cdr Edwin Dunning became the first aircraft to land aboard a moving ship, HMS Furious. Dunning was killed on his third landing when the Pup fell over the side of the ship. The Pup began operations on the carriers in early 1917; the first aircraft were fitted with skid undercarriages in place of the standard landing gear. Landings utilised a system of deck wires to "trap" the aircraft. Later versions reverted to the normal undercarriage. Pups were used as ship-based fighters on three carriers: HMS Campania, Furious and Manxman. A number of other Pups were deployed to cruisers and battleships where they were launched from platforms attached to gun turrets. A Pup flown from a platform on the cruiser HMS Yarmouth shot down the German Zeppelin L 23 off the Danish coast on 21 August 1917.
The U.S. Navy also employed the Sopwith Pup with famed Australian/British test pilot Edgar Percival testing the use of carrier-borne fighters. In 1926, Percival was catapulted in a Pup off the battleship USS Idaho at Guantanamo Bay, Cuba.
The Pup saw extensive use as a trainer. Student pilots completing basic flight training in the Avro 504k often graduated to the Pup as an intermediate trainer. The Pup was also used in Fighting School units for instruction in combat techniques. Many training Pups were in fact reserved by senior officers and instructors as their personal runabouts while a few survived in France as personal or squadron 'hacks' after the type was withdrawn from combat.
The Pup was officially named the Sopwith Scout. The "Pup" nickname arose because pilots considered it to be the "pup" of the larger two-seat Sopwith 1½ Strutter. The name never had official status as it was felt to be "undignified," but a precedent was set, and all later Sopwith types apart from the Triplane acquired animal names (Camel, Dolphin, Snipe etc.), which ended up with the Sopwith firm being said to have created a "flying zoo" during the First World War