Submarines. Great Britain, when not at sea. The largest of these weighs about 15,000 tons. A double-decker bus weighs about 4 tons.

Transcription

1 Submarines A submarine is a ship designed to travel below the surface of the water. It may be used to help us to understand the secrets of the oceans by scientists, by engineers checking underwater oil and gas pipelines, but it is mostly used to help us protect our country, which is an island from conflict and to ensure that vital shipping routes are kept open. If you were asked to design an unseen, underwater fighting machine, make a list of the things you might have to consider before you began your design. How to get air to the crew How to stop the machine being buoyant Fast Fact 1 The Royal Navy currently has 15 submarines sited around the coast of Great Britain, when not at sea. The largest of these weighs about 15,000 tons. A doubledecker bus weighs about 4 tons. 1 Science Technology Engineering Maths

2 The Royal Navy took some persuading that we needed to have submarines. In 1900 Great Britain was the only major maritime power not to have a submarine, which was not a good idea because our battleships could be under threat of surprise attack. Some very traditional officers held strong views Any submariner captured should be hanged as a pirate Unwashed chauffeurs Why do you think that some people held these views? Submarines are underhand, underwater and damned unenglish John P. Holland In 1898 he created the blueprint for the mother of all submarines afloat today. The efficient use of the internal combustion engine and electric motor to power the craft produced the first successful long distance submarine Holland 1 at sea with seven of her eight crew on deck The Holland John Philip Holland was the inventor of the modern submarine. In 1898 he created the blueprint for the mother of all submarines afloat today. His Holland 1 looks very like a whale and explains why the design was so successful! Although submarines have become bigger and more powerful, the basic principles have always remained the same. However in his earliest research, Holland may have conducted experiments like the one you are about to do! Fast Fact 2 In the earliest days The Royal Navy were set against submarines; one admiral even went so far as to say that any submariner captured should be hanged as a pirate. A few years later, a young submarine captain sunk an enemy cruiser which had been threatening our country and raised the Jolly Roger to show the admiralty just what the submarine service could do, as if to say we re not bad for pirates! The flag is still used by submariners today. 2

3 IN A SMALL GROUP YOU ARE GOING TO MAKE A SUBMARINE You will need: an empty 16 or 20oz fizzy drink or squash bottle with a hole in the cap. a flexible straw three wide rubber bands 24 pennies aluminium foil adhesive tape large tub of water scissors or craft knife 1. Cut three round holes in the side of the bottle 2. Make three stacks of the pennies, containing 4, 8 and 12 pennies and carefully wrap each stack with foil. 3. Slide each of the rubber bands around the bottle and position each one of them next to one of the holes that you have made. 4. Place the penny stacks: the 4p stack under the rubber band closest to the bottle s top; the 8p stack under the middle rubber band; the 12p stack under the last rubber band. The coin stacks should be NEXT to the holes, NOT OVER them! 5. Remove the cap from the bottle and pierce a hole in it which will allow you to insert the straw. Try to seal any gaps around the straw hole with tape. 6. Lower the submarine into the water, but keep the straw pointing upwards and if necessary stop water from getting into it by pressing your finger over the open end. Pennies WATCH WHAT HAPPENS NEXT When the sub stops sinking, blow into the straw. 1. What makes your submarine sink? 2. What makes your submarine surface? 3. What would help your submarine navigate underwater? (think back to your lesson on Spitfires) Fast Fact 3 The first ever locomotive torpedo was designed by an Englishman, Robert Whitehead. He was also the great grandfather of the Von Trapp Singers, made famous by the film The Sound of Music.! 3

4 BUT HOW DO SUBMARINES WORK? Complete the following by inserting the right word from the list underneath. Use each word only once. Look at the diagrams to help you understand. Submarines are designed for use at great depths, but they need to be able to sink, to rise and also to They do this by altering their weight with a series of ballast tanks which can hold either or If the submarine s ballast tanks are flooded with., the submarine s weight... If the water is then driven out by the weight By adjusting the amount of water and air in the tanks, the submarine s buoyancy can be precisely controlled. When everything is in balance and the submarine is absolutely static in the water, this is called (1) air (2) float underwater (3) water (4) increases (5) water (6) air (7) decreases (8) neutral buoyancy Fast Fact 4 Very deep water looks dark from above. Submarines are painted black to help them hide. 4

5 10 months after Queen Victoria died, in October 1901, the first Royal Navy submarine, Holland 1 was launched at Barrow in Furness. In 1960, Britain s first nuclearpowered submarine, Dreadnought was launched, also from Barrow. This is where all UK s submarines are still built. BarrowInFurness Compare the capabilities of the two vessels and rank how important you think the improvements have been from 1 8. Then... A crew of eight Now... A crew of about Nuclearpowered travelling both on the surface and underwater of at least 25 knots A petrol engine driving the sub on the surface at about 10 knots. Battery speed of about 7 knots underwater for about 5 hours max A Torpedo propelled by compressed air with a maximum range of about 300 metres Deck gun Visual lookout Able to submerge for 5 hours max Sixty feet long Torpedoes with a range of more than 15 miles Anti ship missile travelling about 70 miles Tactical cruise missiles up to 2000 miles and strategic ballistic missiles. Sonar equipment Nuclear submarines produce own indefinite supply of air water and power. Only limitation to mission is amount of food on board Dependent on model (class) metres long Fast Fact 5 Submarines have to trim their submerged position in the water depending on the water temperature and whether they are in salt or freshwater. 5