The Road Performance of a NEW LOW-LOADER
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The F.W.D. 6-ton Machine Put Through its Paces During the Recent Stormy Weather • DRING the past few years the demand for goods-carrying vehicles with low frame-levels has increased, and when it is remembered that loading and unloading time often proves more expensive than the running costs, the reason for that demand is obvious. One of the latest British low-loading vehicles of large capacity is the 6-ton F.W.D.
During the recent stormy weather we had the opportunity to test an example of this product of Four Wheel Drive Motors, Ltd., 46, Charing Cross, London, &W.1. In the district surrounding the Slough works there was ample proof of the flooded state of the Thames, and many of the roads traversed were partly awash, the rear trailing wheels of the machine being, at times, almost submerged when driving close to the near-side kerb. During the period of the test the wind blew with gale force at times ; these adverse circumstances should be borne in mind when considering the results obtained.
The vehicle was ladert with scrap metal to the full pay-load of six tons; the body was of the platform type with a partially enclosed cab and a fourpiece windscreen. Owing to the absence of a speedometer it was necessary to take all times with the aid of a stop watch and to use a measuring tape. For the same reason it was not possible to measure the fuel consnmption with any degree of accuracy.
On taking over the F.W.D. the colttrola needed a moment's study ; there are two gear levers to be considered. The left-hand one controls first, second and third speeds forward—both high and le* series—whilst the right-hand lever gives high series, low series, top gear and reverse. There are seven forward and^ three reverse Otirs. For all notraal work we found that the right c30
hand lever could be engaged in high series. From rest the machine started easily on the ratio of 28.6 to 1, a change to second being made at once; third speed proved useful for the roads on the Slough Estate and top gear was engaged immediately the main road was reached. At all speeds from 7 m.p.h. to maximum , the top gear was' used, hut on slight up
grades third was engaged at about 34) m.p.h. This change was effected by moving the right-hand gear lever from the top of the gate to the bottom. No normal change of gear demands the use of both levers.
While on the subject of control it should be noted that all gears were easily engaged and there was no need accurately to calculate shaft speeds. The machine which we drove was almost new and the levers were therefore somewhat stiff in operation, but every change was made silently without previous experience on the type.
All the controls were well placed and the steering proved to be cOrnmendably light -for a six-tonner with a forward
driving position. The clutch pedal required a very small effort.
Over a measured mile on a first-class tar-surfaced road the speed for the distance proved to be 22.3 m.p.h. ; during the run there was once momentary check owing to traffic conditions, and the wind was blowing with considerable force from the left front of the vehicle. The best cruising speed proved to be about 15 m.p.h.
In Maidenhead the third (high series) gear proved very suitable for easy running in the rather congested streets. At the foot of the long hill out of Maidenhead, going towards Beading, the vehicle came to rest in the traffic stream and started the climb on first gear (high series). After a few yards second speed was engaged -and held for the rest of the mile-long climb; had it not 'been for a four-tonner ahead, which was travelliog at about 7 the P:W.1).
could have aeeelerated to S and third gear could then 1,104been used. • When descending the sattie hill on the reverse journey no signs of " were noticeable, either when iraking or
whim the vehicle was over-running the engine without braking.
During the test we had occasion to traverse some rough surfaces, and at no time was there any sound from the load. This consisted of scrap metal which was not secured to the platform in any way ; if there had been any highperiod motions of the rear springs' the metal would have been thrown upwards and the consequent noise would have told its own tale. The silence of the load bore testimony to the correct choice of spring length and strength. The front wheels also followed the road contours well, It is important when testing any type of machine to bear in mind the class of work to whin it will be put by the vast majority of users. The F.W.D. lowleader is essentially a vehicle for use upon made roads ; although it will, of course, work well upon softer surfaces, the diameter of the rear wheels precludes the traversing of anything in the nature of freakish terrain. When negotiating deep potholes it proved capable of a steady rate of travel in second r hird speed (high series). . It must be remembered that there were three lower ratios available, so that had the back wheels become bogged, the driver could have utilized the tractive effort of 6,750 lb. so long as the adhesion of the front driving wheels permitted.
The machine in question is of a type well suited to refuse-collection work. This is often most economically carried out if the vehicle be driven along very slowly while the men empty the bins into the container. To ascertain What was the lowest speed of which the P.W.D. was capable we selected a level stretch of road and engaged first speed (low series), 57.9 to 1. The hand throttle was then set to give the minimum speed of which the vehicle was capable without any tendency to 'stall. A Measured distance of 202 ft. was
covered in 2 mins. 381 sees., which .equals a
road speed a .86 m.p.h. This means ' that.: it . vehicle. .of, this ' kind, equipped as a refuse collector, would paSs a house having a frontage of 40 ft. in approximately half a minute.
In a panel reproduced in these pages willbe found many useful figures anent .the specification and performance of the F.W.D. low-loader. Certain comments
upon these will prove helpful. We may remind our readers that the first description of this model appeared in our issue dated October 29th.
The braking results obtained were recorded on . a wet tar-surfaced road. The hand-brake proved slightly the better ; the action of applying each brake was easy and natural, but the pedal gear felt rather !' springy." We understand that certain alterations to improve the power of the brakes are to be made in future examples.
I'eatures of the frame design are that the side members are cranked downwards below the cab and interchangeable rear portions can be used with the same motive unit During the test the surfaces covered presented ample opportunity for frame distortion. A regular look-out through the rear window of the cabjailed to reveal any 'such tendeney.