The Story of the Wonderful Avery Undermounted Engine

Seven Years of Success and Hundreds of Users


| July/August 2004



Ordinary Slack Loose Chain Steering Device

Ordinary Slack Loose Chain Steering Device.

Many More Buy Them Every Year

The Main Points of Advantage Fully Explained by Illustration and Description.

Why An Avery Undermounted Engine Is More Durable

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: