The New Launching Tractor
By Captain Howard F. I. Rowley, C.B.E., R.N., Chief Inspector of Life boats.
LAST year the Institution completed the first of a new type of tractor for launching Life-boats off flat beaches. It was built as the result of six years' experience with tractors at various stations.
That experience had established the tractor as an essential part of Life-boat equipment, but it had also shown that the existing tractors were not sufficiently powerful and that, while successful on sandy beaches, they were not suitable for launching off shingle or very soft mud.
The new tractor was designed to be capable of launching off all kinds of flat beach. It was completed in June last year, and a dedication service and naming ceremony was held at the works of the makers, the Four Wheel Drive Lorry Company. H.R.H. Princess Victoria performed the naming ceremony, giving the tractor her own name, and the Bishop of Buckingham conducted the dedication service.* * A description of the tractor and an account of the ceremony appeared in The Lifeboat for August, 1927.
Immediately after the ceremony the tractor was sent down to New Romney, in Kent, which has one of the most difficult foreshores anywhere on our coasts, and trials were carried out lasting three days. These trials showed that important alterations would be necessary, and the tractor was returned to the makers, who, as they had undertaken to design a tractor suitable to the requirements of the Service, have reconstructed it at their own expense.
They have provided a much lower reduction gear, while using the same 60 h.p. engine, so as to increase pulling power. They have reconstructed the frame to make it stronger, and they have substituted open for closed sprockets f jr the creeper tracks.
Increase of Pulling Power.
The result of these alterations has been to give the tractor a drawbar pull of 15,000 Ib. with total reduction from engine to wheel of 192 to 1, as compared with a drawbar pull in the original model of 6,250 Ib., with a total reduction from engine to wheel of 75 to 1. It is now powerful enough to negotiate the worst beaches, while the change from clostd spr cketsto open enables the sand or shingle to fall in and out of the tracks quite freely, instead, as happened last year, of packing tightly in the driving wheels, with the result that they could not move. Where the tracks slipped round and would not grip, the difficulty was got over successfully by uncoupling, taking the tractor on to firmer ground and then drawing the Life-boat and carriage after her by means of the wireropes and winding-drum which the tractor uses for hauling the Life-boat off the carriage into the sea.
The trials of the new model were carried out again at New Romney, and then at Boulmer, in Northumberland, and Hoylake, in Cheshire, so that the tractor has been thoroughly tested on the worst foreshores to be found—on hard sand, soft wet sand, sand dunes, banks of shingle and soft mud. These trials were so successful that, though they showed that some minor improvements can be made in future tractors, the Princess Victoria, after completing the trial at Hoylake, was at once stationed there in place of the tractor of the old typ3.
Rigorous Tests.
The following are some of the difficulties which the tractor overcame.
At New Romney she took the Lifeboat for 40 yards through soft mud in which the carriage tracks sank to a dfpth of 18 to 20 inches.
At Boulmer, when the tide was at full ebb, the tractor launched the boat after pushing her over about 150 yards of soft sand under water. Where a man sank quickly in the sand up to the ankles, the crecpsr tracks hardly sank at all.
At Hoylake the tractor, Life-boat and carriage were left standing for five minutes on quaking sand, and here j j again they hardly sank at all. At Hoylake, also, the tractor had no difficulty in crossing a bank 4 feet high with a gradient of 1 in 6, and a top of soft mud, and though she could not haul the Life-boat over it when coupled to the carriage, she had no difficulty in doing so with the wire and drum.
It is power and not speed at which we are necessarily aiming in the tractor, but the great celerity with which a launch by tractor can be carried out, as compared with launching by horses and man-power, is shown by the Boulmer test. There, when the tide was very low and the tractor and Life-boat had to travel a third of a mile from boat-house to the water's edge, and then 100 yards out into the sea to reach sufficient depth, the time from the moment of leaving the boat-house to the moment for' launching was only twenty-four minutes..