Compressed Air Fire Engine Shoots Real Stream of Water (Jan, 1932)
Compressed Air Fire Engine Shoots Real Stream of Water
WITH a set of coaster wagon wheels and axles, an old auto gas tank and steering wheel, two tire pumps and odds and ends of lumber, you can build this novel little fire engine which will squirt a stream of water to a considerable height. It is equipped with a powerful brake and a siren, and is propelled by two members of the crew on the push-bar behind. Painted a bright red with bronze trimming it certainly looks like business and furnishes no end of fun making runs to imaginary fires.
The chassis is built up on a 7/8 in. or 1 in. board 12 in. wide and 6 ft. 6 in. long, with 2 in. by 3 in. axles. The steel axles are fastened to the underside with staples, or nails driven part way in and bent over. Note that the king-pin on the front axle is slightly offset so as not to interfere with the steel axle. Use three washers between it and the chassis, and put the nut and lock-nut on the top end. Build up the hood as shown in the perspective drawing, having a diagonal brace and the top horizontal member extending back to serve as a bearing for the steering post. Cut the post the proper length so that there will be ample room under the wheel for the pilot’s knees, and a 3 in. extension below the floor board for a wood spool or drum, which is pinned to it, for the steering cable. The latter can be of sash cord, and should have a stiff equalizing coil spring at one end.
Brace the seat well inside, for it helps prevent the heavy tank sliding forward when making sudden stops. Near the top at the rear solder in two tire valve-stems, and at front on the bottom a nipple to which the fire hose, 1/2 in. rubber tubing, is to be attached. The vent in the filling plug should be stopped and a rubber or fibre washer put under it so that the tank will remain airtight. The tank is secured to a cradle by means of brass or iron straps.
Dimensions of the pump standard, etc., will depend upon the size of the pumps used. The latter should be as substantial as possible, and are secured to a beveled block at the rear of the chassis, as shown. Two holes larger than the screws to be used are drilled in the pump feet so that they can rock slightly on their wood bases. Set the ends of the pump handles in holes in the rocker arm and screw a square of galvanized sheet iron over the holes so that the pump handles will not work sideways. This rocker arm is pivoted on a standard as shown, and at the outer ends sections of 3/4 in. pipe serve as handles. Four boys working the pumps will develop tremendous pressure over the water in the tank and force it out through the hose nozzle to a surprising distance.
In order to steady the chassis while the pumps are being driven full speed a hinged brace drops down from the rear end of the chassis. When not in use this brace is held up out of the way with a hook. The brace, of course, should be made long enough to set firmly on the ground. Note that the brake can also be locked against a block on the side of the seat.
This type of brake is very effective and can be depended on at all times. It consists of a brake beam, the ends of which are covered with sections of garden hose, and is kept clear of the wheels by two light tension springs on the sides of the chassis. A very stiff tension spring is attached on the forward side to keep it tight when the hand lever is locked.
A foot lever can be installed on the left side of the chassis to operate a siren, such as is sold for bicycle use, running off the rear wheel. The push bar is attached to the rear of the chassis, as shown, and has an iron pipe for the handle. This is a safe and effective method of propulsion, as some speed can be attained and at the same time .the pushing members of the crew can help hold the truck back in emergencies.
By all means give the truck a good paint jobâ€”bright red all over, with black and bronze trimmings. A little black and bronze, or gold, sets off the red to good advantage. Paint as much as possible before assembly. Wood axles, brake lever and brake bar, upright for rocker arm and handle bars should be black; floor board and back and bottom of seat gray, and dummy radiator gray or aluminum. The lettering and other trimming can be put on with bronze or gold paint, and when completed you may be assured this little fire engine will be the sensation of your neighborhood.