During the World Wars, Swedish steam locomotives were fired with wood. I convert my Märklin locomotive with an extended tender and a big load of firewood.

Here is the same blog post in Swedish.

(The black-and-white still images in the film are from the Swedish Railway Museum’s photographic archive)

As well as this tender locomotive, I have a tank locomotive on my Märklin layout. It is peacetime and there is no shortage of coal, so the tender is full and a crew of two is enough: the driver and the fireman.

George Orwell’s first novel is called Burmese Days, and I was intrigued to read that the steam locomotive pulling the train from Mandalay was fired with wood. I looked into it and discovered that Swedish steam locomotives were also fired with wood during both World Wars.

A steam locomotive can be fired with almost anything that produces heat. But because wood contains less energy per unit of volume than coal, a greater volume of fuel was needed. The tender therefore needed an extension to carry enough wood for the journey. Another necessary modification was a spark arrester on the chimney, to prevent forest fires.

Firewood came in different forms: short logs and metre-long logs, pure birch and mixed wood. During the First World War, Swedish State Railways built both permanent and mobile wood-cutting plants. Production reached 800,000 cubic metres a year. Even after coal imports resumed, wood firing continued until 1924 to use up the enormous stocks.

Judging from old photographs, the tender extensions were built from fairly heavy timber. I decided on six-by-six-inch posts and three-by-eight-inch horizontal planks. The tender’s entire fuel space was filled with wood. The extension allowed even more to be carried, well above the top of the tender.

Coal flows fairly easily, but logs tend to jam and form arches. So wood-fired locomotives needed a third crew member to handle the firewood. Ideally, he was a strong man who pulled the logs from the tender and passed them to the fireman for the firebox.

He used a long iron pole with a sharp hook to catch and prise loose jammed logs. Swedish State Railways regulations even specified that these men were entitled to leather work gloves.