SHIP’S ELECTRIC LOG

Sun (Auckland), Volume 1, Issue 64, 7 June 1927, Page 9

SHIP’S ELECTRIC LOG

REMARKABLE INSTRUMENT THE IRIS’S RECORDER The Pacific Cable Board’s steamer Iris is the first ship south of the Line to have installed the electric submerged log, a remarkable instrument patented by Captain Chernikeef, and made in London. Yesterday a representative of THE SUN inspected it on board the vessel. Under the direction of Captain H. R. Hughes, Chief-engineer J. D. S. Fleming, and Chief-officer W. Oliver, the working of this new log was made clear. It surpasses anything invented in the past. Instead of having to go aft to read the hand log, the officer on watch can see registered in the chartroom the speed at which the ship is moving and the distance she has run. Instead of the log-line and propeller being trailed over the after-end of the ship, the new log is made a fixture to the hull of the vessel, and is fitted alongside the keel. The log is made of naval brass, and is about 40 inches in length. The outboard portion, which is only eleven inches in length, contains the submerged impulse mechanism enclosed in a watertight casing filled with oil, also the rotator and terminal contact, which is connected by insulated wiring with the battery, and the distance-recorder in the chartroom. This submerged part can be easily withdrawn for inspection or oiling at any time. the recording instrument The distance-recording instrument, which is fitted in an aluminium alloy case, is in the chart-room, the dial being calibrated up to 10,000 miles, but the hands can be reset at any time if desired. Underneath this a speed table is fitted, which shows the speed in half-knots up to 40 knots, and below' this is a blue electric flash-lamp. If the time is taken by a stopwatch between either the commencing or finishing phases of two consecutive flashes, the speed can be read direct from the speed-table. For instance, if the flashes are, say, 17 seconds apart, the ship is travelling at a speed of 10.5 knots. If the ship is at anchor and it takes 72 seconds between the flashes there is a current of 2.5 knots running Past the ship. The electrical power needed to work *his distance recorder is derived from a 6-volt battery, which is sufficient for a 50,000-mile run. SOME ADVANTAGES Some of the advantages of the elec-tric-submerged log is that it is a permanent fitting which, with proper attention, should last a ship a lifetime. •5 ves speed as well as distance, also h will give the speed or rate of a tide current when the ship is an anchor. As there is no other log that will do this, and it works equally as well at :° w s P e eds as it does at high speeds, it should be especially valuable to ships when varying speeds in thick weather, the working of the log is not affected hy the ship’s pitching or rolling in the oughest of weather, and the rotator etng a long way beneath the surface, s clear of all floating obstructions. indicated by the revolutions of ship’s propellers, which is used as ? Eruide by many captains, is subject o sup. which varies according to the , ® of the w'eather, and the condition t the ship’s bottom, etc., whereas the }. ec c-submerged log rotator has no liaKi ** therefore gives a far more retK*r * Indica tion of the ship’s speed a ll Propeller does. tk«l on ® r the to be fitted with ni ! i os are the H.M.S. Rodney, comTrxrS last year; H.M.S. Keppe), Wallace. H.M.S. Raider, H.M.S. s*?® k ®t, H.M.S. Thruster, H.M.S. H 23 H.M.S. Kl 4, all belonging to the T^e Fre nch Navy has 22 logs 4 t * le F>lJ tch 6. Japanese 3. Italian • and Greek 4, while some of the big toi!u nt ! c line rs are now being fitted them.

An illustration of the New Log appears Cn Page 16_