New Zealand January 2016. 2 - internal combustion bush lokies

The timber getters of New Zealand also used internal-combustion locomotives, some incorporating similar principles to those adopted for locally-built articulated locomotives. This particularly applied to the use of a cardan shaft to  power the log bogie immediately behind the locomotive. When the log bogie was loaded, this greatly increased the adhesive weight available.

Truck and tractor technology often provided the basis of these 'lokies'. Most bush tramways were 3ft 6in gauge, the same as the government Railways in New Zealand.

An early type was the Nattrass Patent rail tractor, a Fordson tractor adapted for four-wheel drive and the powering of the adjacent log bogie. These machines were produced by Rail Tractors Ltd of Wellington and some were exported to Australia.

This example is preserved by the Nelson Vintage Engineering & Machinery Club at Wakefield

This one is at Shantytown near Greymouth.
Note the power takeoff which was used to drive a cardan shaft to the following log bogie

Union Foundries at Stratford, near New Plymouth, produced a range of heavily-constructed rail tractors using tractor power units. This one has recently been cosmetically restored at Hokitika for display at Okarito, where it latterly worked.

Dispatch Foundry at Greymouth started building steam articulated lokies but began to substitute petrol tractor engine units from the 1920s, culminating in diesel truck-engined locomotives by the 1950s. A cardan shaft was used to link the bogies under the locomotive with the adjacent log bogie. 

This impressive Leyland diesel model from 1956 is preserved by the Nelson Vintage Engineering & Machinery Club.
Note the massive reversing gearbox under the driving seat.

This 1926 McCormick-Deering version at Shantytown is included to show the cardan shaft drive emerging from the rear axle final drive that would have powered the following log bogie, as well as the centrally-placed reversing gearbox.

A couple of rival companies in Invercargill made similar four-wheeled lokies that could power adjacent log bogies. This example, believed to have been built by H & E Melhop Ltd in the 1940s, had cardan shafts to log bogies behind and in front of the locomotive. Note the wooden rails in this display at Tuatapere.

Because this Melhop unit is lacking its engine, the cardan shaft emerging from the reversing gearbox to power both loco axles and extending to the adjacent log bogie can be seen.
A shaft also ran from the other side of the gearbox to power the log bogie on the other end of the locomotive.

Bush lokie mechanicals were also applied to a whole range of other vehicles used on bush tramways. This rather sophisticated railcar was used by Ogilvie & Co and is preserved at Steam Scene near Christchurch.