In the construction of Top-mounted Engines the Cylinders, Gearing, ground wheels and other parts are all bolted to the boiler by means of brackets. The boiler shell serves as the main frame work of the engine, and must bear all the severe pulling and twisting strains of traction work. Ordinary boiler shells arc only or 5/16 of an inch in thickness and in exceptional cases inch, and think of ita thin shell like this having to carry all the weight of the brackets, gearing, cylinders, etc., and having to stand all the pulling strains.
When you think of this it is easy to see why Top-mounted Engines are not durable for heavy traction work. Every experienced traction engine operator who has used a top-mounted engine for any kind of heavy traction work knows what the results are, for these strains on the boiler cause ail kinds of trouble in the way of leaky cap screws, loose brackets, etc., while in some cases the strains are so great as to even bulge the boiler itself, drawing the gearing out of line and causing the shafting to bind and spring.
But with an Avery Undermounted Engine you get rid of all these troubles. It is much more durable because the boiler is entirely free from all pulling strains. The entire working partscylinders, gearing, ground wheels, etcare all mounted on an independent angle steel framework. The cylinders are bolted to the steel framenot the boiler. The gearing and ground wheels are all fastened to the steel framenot the boiler. The load is all pulled by the steel framenot the boiler. There are no pulling strains whatever on the boilerthe steel frame work takes them all.
In building a Top-mounted Engine, the first thing you do is to begin boring holes in the boiler to attach the brackets. In an Avery Under-mounted Engine, you build up the truck all complete, and then simply set the boiler on and bore enough holes in it to fasten it on and hold it in position. The boiler carries no weight and pulls no load.
The line drawings of the Top-mounted Engine and the Avery Undermounted Engine on this page show clearly why an Avery Under-mounted Engine is much more durable than the Top-mounted style. In this Top-mounted Boiler there are 108 boles bored in the water space for attaching the brackets. In the Avery Undermounted Engine there are only 18 holes bored in the water space in the open bottom boilers and 38 in the closed bottom boilers. Only 1/6 as many bolts in the open bottom style and about 1/3 as many in the water bottom style, and these bolts in an Undermounted Engine Boiler have practically no strains to bear, while in a Top-mounted Engine they have to pull all the load and hold the engine together.
To emphasize stronger what this all means to you when you buy an Avery Undermounted Engine, we give every purchaser a special warranty against leaky brackets which is printed right in our order blank. This warranty reads as follows:
All Avery Undermounted Engines are warranted for one year or LONGER against leaky cap acres attaching any brackets to the boiler, and any defects of such nature will be made good free of charge.
Notice that this says one year or longer. There is no time limit to this warranty, and it covers one of the worst troubles owners have with Top-mounted Engines. Where can you get any such a warranty as this on any Top-mounted Engine?
It is surety plain to see from all this that an Avery Double Under-mounted Engine with its independent boiler has a construction that will last much longer and stand up in better shape under heavy palling strains than a Boiler-mounted. Bracket-type Engine. This is a point that you could consider strongly in buying an engine. The engine that is cheapest for you to buy, is the one that wilt stand tip under the work and keep at it day after day and last the longest.
There are three principal reasons why an Avery Undermounted Engine is More Powerful on the. draw-bar pull.
The first reason is that with the Avery Undermounted Engine, the load is distributed better proportionately on the front and rear wheels and there is no rearing or jumping up of the front wheels as often happens with Top-mounted Engines when pulling heavy loads.
The second reason is found in the fact that the pull of the cylinders through the gearing and back to the load is in a straight line instead of down from the top of the boiler at an angle as with Top-mounted Engines.
This is clearly shown by the two drawings here and is one of (he most important reasons why an Avery Undermounted Engine is more powerful on the draw-bar pull.
The third reason why an Avery Undermounted Engine is more powerful, is because it has two cylinders, is equipped with balance valves and has a specially designed curved block valve gear. With the double cylinders you never have any dead centers, you can start a load much easier and with less-jerking on the engine and the load, and get a steadier pull and more power. The balance valves save steam, relieve the valve gear of much of the strain required to move the ordinary slide valves, and help to increase the power of the engine and reduce the amount of the fuel, water and lubricating oil required. The Avery valve gear gives an equal lead and cut off at all points with the reverse thrown clear over or hooked up, and whether the engines are running in one direction or the other.
When you buy an engine what you want is power. Power for belt driving and power for pulling. We cannot make this point too strong about the wonderful power of an Avery Undermounted Engine, Remember this, that you get more power when you buy an Avery Undermounted Engine than with any other engine built.
The illustrations here show better than words why an Avery Undermounted Engine is easier to handle.
The two illustrations above show how you have to climb up on top of the boiler to oil or adjust a Top-mounted Engine, while on an Avery Undermounted Engine you can reach all the working parts while standing on the ground.
The illustration here shows three men belting up a Top-mounted Engine. One man is up on top of the drive wheel and the two men on the ground are lifting up the belt.
With an Avery Undermounted Engine, one man alone can stand on the ground and put on the drive belt and do it easier and quicker than two or three men can put the belt on the fly-wheel of a Top-mounted Engine.
These illustrations show you how you fire a Top-mounted Engine and an Avery Undermounted Engine. In one, the fire door is down close to the platform, and you have to lean over and bend almost double to throw in the coal. With the Avery Undermounted Engine you can stand almost straight up to do the firing.
These illustrations show the style of the ordinary loose chain guide and the Avery Screw Shaft Steering device. In the chain style it is necessary for the chains to be loose, and each time you turn the steering wheel from one way to the other, you have to take up the slack in the chain. The wheels continually jerk backwards and forwards and the engineer is kept busy keeping his engine in line.
In the Avery undermounted Engine, we use a Screw Shaft in place of chains. There is no slackness at all in the steering device. When you begin to turn the steering 'wheel, the front wheels also begin to turn immediately. There is much less turning of the steering wheel required. The slackness of the ordinary chain guide is entirely done away with, steering made much easier and more positive and the wheels move ahead directly in line where they are set. The arrangement of the gears is also such that you can turn the front wheels much more easily than with the chain style. This is a particularly valuable feature' for plowing, grading or hauling purposes.
The Avery screw shaft guide is the finest tiling in the way of a guide that was ever put on an engine.
Consider all of these thingsbeing able to get at the working parts while standing on the ground for oiling and adjusting and not having to climb around over a hot boiler; the fly-wheel low down so that one man can belt up the engine and stand on the ground to do it; the convenient location of the fire door which makes it much easier to fire; and the positive, easy working, screw shaft, slackless steering devicewhen you consider all these things, you will easily understand why an Avery Undermounted Engine is much Easier to Handle than other engines.
You ought to find out all about the Avery Undermounted Engine. The Engine that's built like a railroad locomotive. The Engine that's More Durable, More Powerful and Easier to Handle. Write for free copy of our new 1911 Avery Engine, Separator and Plow catalog and find out all about it. Address