Demonstration of Thrige power station


I visited one of the monthly openings at an old power station from 1916 that is still operational, it is only maintained and started up to give a demonstration of a beautiful piece of machinery to the public. A small group of volunteers maintain and run the generator and museum.


The engine is according to B&W the oldest running 4 cylinder B&W diesel engine in the world. The engine was manufactured in two versions, one for land and one for ships, the difference was that the ship version could reverse.

  • B&W- DIESEL ENGINE type 4.124 L (L stand for Land engine).
  • Build year 1923.
  • Fabrication number 984.
  • 4-cylinder 4-stroke trunk engine at 500 HK.
  • The engine was first started for test the 21st june 1923.
  • Engine length: 7.150 meters  (5.700 meters without generator and dynamo).
  • Engine width: 1.700 meters.
  • Engine height: 4.100 meters.
  • Weight: 57000 kilogram.
  • Piston diameter: 480 mm.
  • Stroke length: 700 mm.
  • Stroke speed: 4,375 meters / second at 187,5 RPM
  • Fuel usage: 90 kilogram/ hour at 1/1 load ( 700 amp. DC.)
  • Efficiency at 1/1 load: 76%

The B&W diesel engine does not have a starter engine, but uses compressed air to get the pistons up in a speed where the fuel can take over, the compressed air is also used to dust the fuel when the engine is running. The dusting pressure can reach 65 bar but the engine runs best around 45-50 bar.

  • Start air pressure : 65 bar.
  • Piston surface pressure at start 1808,64 cm² x 65 kg. = 117,56 ton
  • Fuel dusting pressure: 65 bar.
  • Fuel prepump pressure : 5 bar
  • Four stepped compressor takes up 25-30% of the engines power ~ 125 HK

The high voltage generation consists of a AC and DC generation from the following generator and dynamo.

  • AC generator produces 685 ampere at 380 VAC
  • RPM = (60 x frequency)/16 pole pair = (60 x 50)/16 = 187,5 RPM
  • DC dynamo produces 700 ampere ar 480 VDC


Their official homepage, only in Danish:

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