BRITISH ENGINEERING PROGRESS.

Northern Advocate, 23 June 1920, Page 4

BRITISH ENGINEERING PROGRESS.

A NEW iVIOTO.IMdF.EIiOAT

The work of the .National Lifeboat Institution of Giteat Britain was largely held up during the war, but an extensive programme of boat-buililing has since been -tartod. it includes a nura-

ter of motor-propelled HiV-boms, this typo having proved its superiority. On one occasion a moior lifeboat travelled forty-foml miles in n terrible .storm and rescued fifty people from a vessel which four other lifeboats of the old type had tried in vain to reach. One of the latest motor lifeboats to be put in commission has. many interesting features. It is of the self-righting type and is driven by a 45 horse-power petipl engine at a speed of about eight knots. When a lifeboat capsizes ii is necessary to stop the engine, as otherwise the boat will steam off and leave its crew in the water. This condition is met by means of two contacts in an ebonite box with mercury, so arranged that, when the boat is sailing normall;- the contacts arc immersed in the mciicury. When the boat capsizes, the mercury is emptied out into a little reservoir and breaks contact, stopping the engine. Elaborate "jacketing" i.s resorted to in order to prevent watci] getting into the engine. Both magneto and accumulator ignition jre installed, and a band pump is available as well as the force feed system of lubrication. These and other precautions arc adopted in order to prevent breakdown. RESTARCH IN CORROSION.

At the recent congress of the British Institution of Metals a valuable report ■was read on the corrosion of .condenser tubes—a subject in which so'many engineers "are keenly interested. This re-, ■port-was-the fifth of .a series, recording •iroseare-hos undertaker'by a special committee of the Institute. Experiments have -been made witb! alloys of copper and zinc, and many suggestions made, for avoiding or reducing corrosion. In the British Navy trials are being made with oxidised tubes, and a British company has been formed to exploit an electrolytic process -vhich deposits and maintains a protective layer of lime on ihc- surface of the tid-e. BRITISH ENGINEERING EXHIBITIONS.

The Machine Tool Trades Association of Great Britain has arranged to hold an exhibition of machine tools and kindred engineering products in Olympia, London, during the coming autumn. Practically the whole of the available space, which is very extensive, has already been booked. The British Eleetifical and Allied Manufacturers' Association will hold an electrical exhibition, probably in the same building, during 1922. A FAMOUS MOTOR BOAT. At, the recent Motor Boat Exhibition in London, the most attractive exhibit was the famous coastal motor boat C.M.8.4, from the Baltic after many cruises, during which she passed through lines of forts and toupedoed the Bolshevik cruisev Oleg. This- vessel is a skimovcr or hydroplane, of the typo invented before the war for sporting purposes. It attains a speed of 40 knots with full armament and crew. The show contained many Bnitish examples of small auxiliary motors which can be attached to rowing boats and other small craft. Some .of those are installed on board and others are attached to the stern withtout structural alterations. One pattern, with an engine rated at two to three house-power, weighs only 601bs complete with propeller and steering gear.

TIDAL POWBB SCHEME,

The Ministry of Transport in Great Britain is giving careful attention to the possibility of building a dam across* the estuary of the Severn ih orden to generate electric power from the tidal waters. The Ministry has also formed a strong committee to examine the ambitious schemes for electrification put forward by several British railway companies and to lay dosvn principles which will lead to uniformity in electrical and mechanical matters so that through running will eventually b-j feasible.

A GIANT BATTLE- CBUISER

The British battle-cruiser Hood, begun in September 1910, launched in August 1918, and recently completed, represents many of the latest advances in man-o'-wav design and construction. A prominent feature is the "bulge" or "blister" which surrounds the main hulL of the ship, below the water line and protects it against torpedo attack. The Hood carries eight 15-inch guns, all on the middle line of the vessel, and there are twelve 5.5 inch guns, four 4inch anti-aineraft guns, and six torpedo t.ilies. The propelling machinery consists of four distinct sets of turbines, each driving a separate shaft through gearing. Together they develop the huge total of 144,000 horse-power. For various auxiliary purposes there are 300 electric motors, and some of the pumps fire of the submersible electric typo which operates under water. Nearly three thousand incandescent electric lamps arc used on boand, in addition to electric fires and cooking apparatus. On the trial trips the turbines developed 157,000 shaft horse-power, and propelled the vessel at a speed of 32 knots.