From the Military History Journal (Volume 4 No 1 - June 1977) there is an article entitled BICYCLES IN THE ANGLO-BOER WAR OF 1899-1902, by D.R. Maree, which seems to fit this question.
The 'War Cycle' carried several men on the coupling-framework in addition to the eight riders,
could be fitted with a Maxim gun, and was capable of a speed of over 48 kmh.
Photo: Africana Museum
A special 'War Cycle' was built for use on railway lines, and a prototype of this 8-man bicycle can be seen at Fort Klapperkop Museum. It was introduced into South Africa by the Royal Australian Cycle Corps and had a detachable rim which was fitted to the pneumatic tires, enabling it to be used on rails. When the rim was removed the bicycle could be used on normal roads. These cycles were used for reconnaissance, for carrying despatches, checking the railway line for demolition charges, and also for removing the wounded from a skirmish taking place near a railway.