Fire Truck Contract Awarded to Mack
The recent award by the New York Fire Department of a contract for ten four-wheel tractor drawn aerial hook and ladder trucks to the International Motor Company, manufacturers of Mack fire apparatus and commercial trucks, has created wide interest, for in the past New York has purchased only front wheel drive apparatus for this service.
There has always been a difference of opinion regarding the type of tractor best adapted to long trailing apparatus, and the New York Fire Department by advertising for bids on both two-wheel and four-wheel tractors, recognized that both types have merit.
That the choice was made in favor of the four-wheel tractor, however, indicates that this type possesses advantages over the two-wheel tractor for use with aerial hook and ladder semi-trailers. It appears that the four-wheel tractor with semi-trailers offers greater flexibility of operation than would ordinarily be expected of a vehicle of such great length. This is made possible by the fact that the front end of the semi-trailer is mounted upon a wagon type of fifth wheel which rests on the tractor’s rear end or driving axle. This fifth wheel functions exactly the same as the fifth wheel of a horse drawn wagon, and the combination of tractor and semi-trailer folds on the king pin when turning. The vehicle can thus be turned completely around without the trailing wheels moving out of a ten foot circle.
The two-wheel tractor with semitrailer, on the other hand, is in reality a four-wheel, long wheelbase truck driven through the front wheels. Unlike the four-wheel tractor, it requires a very wide street in which to turn completely without backing, and finds difficulty in maneuvering in confined places. The four-wheel tractor is not handicapped in this way, but can negotiate sharp corners on narrow streets because of the more flexible combination of the tractor fifth wheel and the rear wheel steering mechanism on the semil-trailer.
Another favorable feature of the four-wheel tractor is the accessibility of its power plant and driving mechanism, for it is built like a short wheelbase truck. In the two-wheel tractor, the engine and machinery are placed in relatively inaccessible locations, being largely under the driver’s seat.
These ten aerial hook and ladder trucks will be built complete by the International Motor Company. The New York Fire Department now has one hundred and twenty-two pieces of Mack motor fire apparatus in use, and fourteen on order. The first Mack was installed in 1911.