# The Engine Collection

The Engine Collection (Danish: Dansk Motor- og Maskinsamling) is a museum in Grenå, Denmark. The museum is Northern Europe's largest collection of stationary engines, with over 450 engines on exhibit, most of which have been restored and are functional.
The museum has a machine shop for dismantling and rebuilding engines, and new parts are made, when necessary. The museum also exhibits some historical machinery, such as a bandsaw-based sawmill driven by a Bukh engine via an elaborate belt drive that connects the indoor engine with the outdoor sawmill.

## Organization

The Engine Collection is a foundation based on volunteers with many special skills, such as mechanical specialists in the field of engine restoration. Restoration tasks may include milling of new cylinders, pistons, and glow heads with the contours of the old rusted parts as models, as well as manufacturing of engine parts that are missing, damaged, or rusted.
The collection has a club of working supporters. Many members have a background in the engine building or the metal industry, or have other skills and resources needed to undertake the maintenance and expansion of the engines at a mechanical restoration institution and museum.
The collection's finances depend on donations from foundations and private sponsors from industries in related fields and are interested in preserving the history of technology. These donations are used to provide equipment and manpower to the museum. One of the donations included ship transport with a tug boat, cranes, and a flatbed trailer when three large B&W engines from the deserted military island Flakfortet in Øresund had to be moved to the collection for restoration. The flywheel alone for these engines weighs 1.5 tons.

## Exhibition

The engines are exhibited in several buildings, which are being expanded as the collection grows.
The primary focus at the Engine Collection is stationary internal combustion engines, from the earliest atmospheric Otto & Langen engine of1868 to engines from 1960 to 1970. The collection has a special interest in Danish engines but has also restored and exhibited many other engines. Manufacturers often copy each other's concepts and improvements in disregard of national borders and brands.
It can be a logistical challenge to get large engines weighing several tons moved from old factory buildings and plants to the collection. Once, three rusted and vandalized B&W DM 220 diesel engines from 1914 were transferred from the electricity works at the Flak Fort (Flakfortet) bunkers on an uninhabited island in Øresund by Sealand in 2002.
The engines in the collection are mostly run for arrangements and events. They are also started up for prebooked groups.
The oldest engine in the collection is from 1868 and is from the very early days of the internal combustion engine. It is an Otto and Langen "Atmospheric Engine" running based on a vertical cannon principle, where a piston is shot up without pulling and fired by town gas in a freewheeling stroke. After the explosion, the piston goes down, causing the vacuum from the contraction of the exhaust gas, plus gravity, to move the piston down, driving the engine. The design has no camshaft. An array of handmade cogged wheels transfer the piston motion to rotation. The engine speed is regulated via opening and closing of the exhaust valve. The Otto and Langen engine is on loan from The Danish Technical Museum but is housed at The Engine Collection, where it was restored. The engine is one of the world's oldest internal combustion engines according to the Engine Collection. The name, Otto, is also seen in the Otto-Motor synonymous with the conventional 4-stroke engine, which was invented by Niklaus August Otto (1832–1891) a little less than a decade after the same Otto co-invented the atmospheric engine. The Otto engine is a technological pillarstone of modern society. For example, the 4-stroke Otto-Engine is the working principle behind the car engine.

## Power source development

After the heyday of the steam engines, and before electrification led to electric motors being the main power source for machines, the stationary combustion engine was an important power source in industry and farming. The stationary internal combustion engine outcompeted the steam engine and was then outcompeted by electric motors. The electric motor was more compact and demanded less maintenance. In Denmark, the transfer to electric motors mainly occurred between 1920 and 1950.
There is a large representation of different makes of 2–10 Hp stationary engines at The Machine Collection. The demand for these smaller engines was driven by an, at the time, important farming sector in Denmark, that not only supplied the home market but developed a significant export, not least bacon and butter to England. On farms the stationary engine was typically placed in a separate machine house, where the engine was started at least twice a day, powering a compressor for milking equipment. These below 10 Hp engines on farms were also used to power other machinery such as threshers and grinding mills.
One reason for the focus on Danish engines at The Engine Collection is that there were more than 200 stationary engine manufacturers in Denmark in the golden ages of Danish industrialization, which was 1890–1930, often with their own foundry. A similar multitude of manufacturers were found in some other countries. The emphasis on Danish engines at The Engine Collection is also because the largest Danish manufacturer, B&W, held nearly 50 pct. of the global market for ship diesel engines in the late twenties, making it one of the technology leaders at that time. These often-large B&W engines were also used as stationary engines at electricity plants to power generators, and as power sources for factories, starting with the elaborate belt-driven distribution of power to machines in the factory, ending with driving a generator, supplying the machines with power through electrical cables.

## Ongoing projects

Under "Ongoing projects" on the homepage (in Danish, but with pictures) of the Machine Collection, one can follow current restoration projects such as an IF Fleetstar 2050 A lorry from 1971 with a V-8 engine and an ash-wood inner frame cabin.
A recently (2014) completed restoration project is a Danish, Eickhoff, engine from 1887. Some of the engines in the collection are one of a kind, such as a Rudolf Kramper engine from 1927, which may be the only one left in the world.