Coolspring Power Museum Air Blast Injection Building Update

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courtesy Dr. Paul Harvey

In the August/September 2021 issue of Gas Engine Magazine, I wrote The Benz Engine story and mentioned how it would fit into CPM’s new project being the Air Blast Injection (ABI) building. We are certainly happy with the progress and this article will explain why. This update is intended to tie the project together for the reader to better understand our excitement.

What is air blast injection?

I’ve talked about that for quite a while, so it’s best I explain. We will now time travel to 1893, to visit Dr. Rudolph Diesel in Augsburg, Germany.

He had an idea and a dream. Being an impeccable engineer, he was skilled in mathematics. Although Nicholas Otto’s gas engine had been around since 1876, Diesel thought he could do him one better. He calculated that if compression was increased, the resulting temperature in the cylinder would increase. Wow, inject the fuel at the correct time and no other means of ignition would be needed. He also wanted to inject the fuel over 20 degrees of crankshaft rotation, prolonging the amount of power. The Otto gas engine had an instantaneous explosion to provide the power. It sounded great, but how would he make it work?

Dr. Diesel was fortunate to align himself with Maschinenfabrik Augsburg, which was already building a large array of equipment and had facilities for his engine construction and trials. He and his staff worked diligently from 1893 to 1897 to perfect the engine. There were many trials and failures in trying to develop a cylinder to withstand the needed 500psi compression for ignition. Some prototypes actually exploded!

Solving this, he was next faced with the problem of getting the fuel injected into the cylinder. Finally he developed a plan to deliver the fuel to the injector under low pressure then used 850psi to blast it in at the precise time. It was a success! He had developed air blast injection. His first successful engine of 1897 is proudly displayed in the MAN Museum in Augsburg.

Diesel’s engine was an instant success and Maschinenfabrik Augsburg met the large demand, building these magnificent machines in much larger sizes. CPM’s Augsburg is 12hp and was built in 1903 and is SN 185.

Engines to be displayed at the Coolspring Power Museum

Now what about CPM’s exciting new building and the engines it will display? It will contain the Augsburg, the Graz and the Benz. More about them later. The good news is the structure will appear as an early 1900s German powerhouse. Our friend, Dr. Friedrich Busch, provided an excellent photo of a 1904 German structure. We intend to duplicate it as much as possible, including the lighting and the tile flooring.

Gordon Jones and I have been working closely with CBF Contracting of Sligo, Pennsylvania. They have provided extensive drawings, and construction will soon begin with the Benz and Augsburg foundations, as well as the building footers.

The site was cleared of five dead trees and lots of storage items. It’s just north of the water tower and across the road from Pat’s Place.

The structure will be 30 feet wide and 40 feet long to provide an ample visitor area. It will have a red brick exterior with a reproduction tile roof – much like the original German powerhouses. The doors are wooden and swing out on massive iron hinges. There will be porch roofs over the south and east doors. The floor will be black and white tile around the engines to match the vintage style. The center will have commemorative paver bricks in the floor (see sidebar to right). The walls will be tiled up to five feet then stuccoed in white to the ceiling. The interior ceiling will be open trusses.

I’m sure it will be a world class display, there is no other place in the world that has such an installation. One can just step back 100-plus years upon arriving. What an experience!

We are doing fund raising in several ways. The commemorative bricks have been quite popular, available in many costs and inscribed as one wishes.

Of course, the first engine to be included is our MAN, or more appropriate, Augsburg. This engine was built in 1903; Augsburg and Nuremberg did not merge until 1908. When completed, it will be the oldest running Diesel in the world.

It was originally bought by Siemens and Halske who fit it with a DC dynamo and sold it to the island of Helgoland to power a lift/elevator to transport tourists.

The second engine is the 1918 Benz. Admittedly, it is not air blast injection, but it was built in Germany and represents 15-plus years of Diesel engine evolution. The classic design allows it to blend well. The German design should complement the display.

The third and final engine will be the Graz that is being acquired from Dr. Friedrich Busch of Hof, Germany. All was ready to import last year, but then Covid struck. I had planned to return to Germany with several friends to learn its operation then help dismantle it and pack it for the voyage to CPM. Perhaps this year we will see that happen.

The engine was built by Grazer Waggon & Maschinen Fabrik of Graz, Austria. It is also 12hp – as all three are – and built under Augsburg license in 1904 as SN 19. It will be a great addition to have two significant air blast injection diesels in the same building.

I certainly hope you have enjoyed this little tour of our exciting new building and the equipment it will contain. It is an ambitious project but the results will be rewarding. Please consider helping us in any way you can.

And now, back to my rocking chair …

For more information on the Coolspring Power Museum, to contribute to the ABI Building project or purchase merchandise, visit the Coolspring Power Museum.

Email Dr. Paul Harvey at

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