The 1908 Tender for L.C.C. Motor (Escape) Vans.
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A form of tender and specification has been issued, after due advertisement, in this and other journals, by the London County Council, for petrol-driven motor (escape) vans for the London Fire Brigade. It will be remembered that a similar tender was invited last year, on which occasion, however, a single van, with a possible additional one, was stated to be required. In the present form of tender, the Council asks for prices from contractors for one escape-van, or, " at the option of the Council, two, three, or four vans for the use of the London Fire Brigade." The actual terms of the specification, in certain of the sections, are of considerable interest to those who study the employment of commercial motor vehicles.
This year, the Council is asking for a machine to be fitted with an engine of larger power than those on the escapevans which it has already purchased. The clause dealing with this point reads : " The engine to be of not less than 3o-33h.p., with four or six cylinders, and mechanicallyoperated valves." Last year, the Council was satisfied with 4oh.p., and a four-cylinder engine was specified. The reclues!, for increased horse-power is evidently due to the necessity of maintaining a higher rate of speed on the level, and of doing work at a greater rate on hilly roads, than has been provided for hitherto. The official request for an alternative six-cylinder engine is of considerable novelty, and, although it makes for increased cost, such an arrangement might not be without its advantages, in that a sixcylinder engine should certainly be more easy to start than
four-cylinder motor of equal power and with correspondingly larger piston areas.
Higher Speeds Found to be Necessary.
According to section 3, considerable alteration is to he made in the speed which the contractor is to guarantee under varying circumstances. Last year, zo miles per hour on the top speed was considered sufficient ; but, this year, the new machines are to be capable of the following performances :— " 23 miles an hour to be maintained on the top speed, with full load, on the level, on a good road, and, on the bottom speed, the machine must ascend any hill in London, with full load, at a speed of not less than five miles an hour, in any weather. The steepest gradient is believed to be i in 6L-." The authorities have thus thought it necessary, in the present specification, to insist that a minimum speed shall be maintained on the worst hill Which would have to be encountered in service, and to insert the stipulation that the machine should be capable of carrying out this performance " in any weather." In 1907, the steepest gradient was suggested as being i in 7. We estimate that the total weight of the van in service trim Will be nearly five tons.
Type of Quadrant for Change-speed Gears.
Both this year and last year, a gate change-speed lever has been stipulated, but, as Commercial Cars, Limited, on last year's contract, supplied two of its well-known vehicles, and we are assured that they have been giving every satisfaction, it is to be presumed that this requirement will not be rigidly enforced. The " Commer Car," as, of course, is well known, has a special type of change-speed gear which is entirely its own, and which does not conform to the L.C.C. specification in this respect.
Metal-to-metal Clutches.
In paragraph 4, the Council still insists, as last year, on the inclusion of a Hele-Shaw or other approved metal-to. metal clutch, and a chain drive by Brampton or Hans Renold. In it evident that the authorities will not entertain the use of the simple and well-known leather-faced coneclutch for fire-brigade purposes, where the clutch, with most of the other details, is liable to have to undergo barbarous treatment occasionally. The size of the chains is specified this year to be " 11-inch pitch, inch wide, with one-inch rollers." Gearbox details, change-speed gear, steering gear, brakes and springs, further than a stipulation that they shall all be of specially strong design, are left largely to the designing capability of the contractor.
Engine Control.
An interesting modification in the London Fire Brigade's requirements is shown in section 6 of the specification, which deals with the control of the machine generally. Last year, it was distinctly specified that the hand-control levers for the engine were not to be placed on top of the steering wheel ; this year, permission is given so to place them, providing, of course, that they do not move with the wheel. As before, stipulation is made that no throttle valves shall be attached to the foot-brake, and that the clutch shall not be thrown out of gear by the foot-brake pedal. Last year, it was stated that a font accelerator might be provided, whilst, this year, such a device is expressly forbidden. On both occasions, however, a governor or suitable throttle has been insisted upon, and this has to be arranged to stop the engine from racing when the clutch is disengaged. As, under the new specification, no foot accelerator is to be provided, it will be a matter of considerable ingenuity so to adjust the governor that it will allow the engine to run at a high speed when in gear or when the load is being started, and yet will cut it out when the clutch is withdrawn : it would seem that some kind of control of the governor is necessarily implied.
Ignition Details.
Paragraph 7 deals with ignition, and the choice is again given between two alternative, combined systems, viz. (a) ILT. magneto, in conjunction with art accumulator, a single coil, and a disfributor ;.or (b) a L.T. magneto, with a similar accumulator-coil outfit. Each combined system is to consist of two distinct installations. This year, however, . the Council has specified the makes of fittings it will accept, viz.': a Simms-Rosch (sic) H.T. magneto ; " Oleo " or " Pognon " plugs; a Simms L.T. magneto; and a single " Fuller "or other approved make of coil.
Radiators.
Paragraph 9 deals with the radiator, and it is evident that the authorities do not like the cellular type of cooler. Last year, the gilled-tube type was specifically mentioned, and this year the radiator is to be of the flattened tube, or other approved type,
The Turning Circle.
Paragraph io reduces the circle, in which the machine is to turn, to a diameter of 43 feet 6 inches, or less if possible. Last year, the Council was satisfied with a so-font circle, according to its specification.
Brakes—a Flaw.
The question of the brakes has always been one on which fire-brigade authorities have had their own special views, and, strictly speaking, these views have not coincided with those of designers who are responsible for the evolution of modern motor vehicles, either for pleasure or commercial use : a third brake, to be operated by the foot, is to be ar. ranged on the left of the driver, in order to be accessible to a second person seated on the near side. To most people who are familiar with driving conditions, the necessity of having the whole control of any motor vehicle immediately at the driver's command appears a necessity, and the provision of a device which relegates part of this responsibility to another person seems inadvisable, and liable, in this instance, to lead to the uncertain control of a heavy machine which is capable of travelling at high speeds. The brakes under the sole control of the driver should be made ample to stop the vehicle rapidly in an emergency. Of course, the horse-drawn machines, both steamers and manuals, are all provided with hand brakes, which are operated by spec:al brakesmen, and the horse driver undoubtedly relies on the synchronisation of others' efforts with his own. It is not difficult to imagine the state of mind of the driver who is makingat full speed for a narrow gap in the traffic, which he feels, if he is there in time, he can just utilise, when, at a critical moment, the independent brakesman slows the machine, and it gets to the gap just too late I Wheels and Tires.
Section 13 deals with the wheels, tires, axle arms, and mudguards. As before, the wheels are to have their hubs bared to fit a sample pattern of axle arm, which this year is
inches long, and, in 1907, was stated to be7,1 inches long-. We think this is a stipulation which will not find favour with the majority of contractors, as it will necessitate
modification in their standard designs, and it is, surely, feasible to imagine that the manufacturers of heavy motor vehicles are by now in a position to decide as to what is a suitable size for such a fitting. It is probable, however, that this proviso is made solely to ensure standardisation and ready interchangeability of the wheels. All wheels are to be fitted with de Fournier or similar tire protectors, and the tires, which are to be four-inch solids, are to be carried in "Clincher " rims, and to be not less than al inches thick.
It is surprising to note that the Council now asks that all the tires shall be single : such a course almost points to the fact that the authorities must have failed in securing im
munity from side slip by the employment of twin tires, on the hind wheels, or, it may be, of course, that there are other objections to the employment of twin tires for this work.
" The wheel base to be not less than ii feet 6 inches, and the track of the front wheels such that they do not both run in tramlines at the same time. Width for the felloes of hind wheels not to be more than 5 feet 4 inches." This section, but for the addition of the width across the hind wheels, remains as in the previous specification.
Illumination.
Rather an elaborate system of illuminating the vehicle is to be provided : two, " Alpha," brass, acetylene head-lamps, with electrical means of lighting from the dashboard; one paraffin tail lamp, with mechanical (sic) means of lighting; and two, Lucas, No. 744, brass, paraffin head-lamps, with mechanical means of lighting, as well as brackets to take the ordinary copper, brigade-pattern, carriage lamps, are all called for. We, at the time of writing, are not aware of any successful method of "mechanical " lighting for paraffin lamps which is on the market, although several arrangements have been tried; the electrical method of lighting an acetylene lamp is practicable, but it has been but little adopted on either commercial or pleasure vehicles.
A Single Contractor.
Sections 14 to IS deal with the carriage of the escape on the 'chassis, and give details of the different fittings which are to be provided to enable the machine to carry the numerous accessories. A large chemical tank, two extincteurs (against one last year), steel air bottles, and lengths of Dermatine, four-ply, indiarubber hose have to be provided under the contract.
We presume it would not be convenient to divide the contract so that the chassis might be supplied by a first-class motor-vehicle manufacturer, and the fire-brigade appliances might be fitted by some maker who has specialised in this direction. No motor-vehicle manufacturer is in a position to supply fire-brigade fittings of his own make, and we question whether firms which have for many years specialised solely in the production of fire-brigade appliances are in a position to produce such satisfactory motor vehicles as are manufacturers who have been solely engaged in this direction for a long period. The Council, of course, finds it necessary to limit the responsibility for the complete machine to one contractor, but it is doubtful whether, at the moment, this will result in the production of a satisfactory combination at the lowest possible cost, as the motor manufacturer has to pay excessive prices for all he buys.
The remainder of the 1908 specification deals entirely with the terms under which the contractor manufactures, supplies, and delivers the machines, and calls for no special comment.