Caterpillar D4 in Longman Workshop
Photograph courtesy of Sandy Gordon, Nairn, who worked as a mechanic at the Forestry Commission Workshops at the Longman, Inverness from around 1977 to 1984.
This special Caterpillar D4 with extended drive shafts and gear housing to accommodate the extra wide track plates was categorised as D4 SLGP (D4 Model Super Low Ground Pressure) and capable of pulling a plough on the deep peat flows of Caithness and Sutherland. The main tractor driver for most of its working life was Donnie Junor from the Black Isle.
The main component of the track was the non aggressive Apical Track Plate with extensions added to either end. The shaped curve on the apical plate allowed the tractor to turn quite easily on the soft peat without tearing the load bearing vegetation off the surface. From memory the entire machine was over 12 feet wide and forest gates were adjusted to 4 meters wide to allow entry. It certainly had an impressive capability on very soft peat where there was some risk of a person sinking when walking over it.
Considerable effort and ingenuity was exercised in developing systems to plough the deep peats and plant trees during the 70s and 80s. Ironically now considerable effort and ingenuity is again being exercised but this time to reconvert these young peat land forests back into peat bogs to retain the carbon locked up deep wet peat.
Groups: Tractors Ploughs and Drainage Machines