NARROW GAUGE sugar cane railways in Cuba, Indonesia and elsewhere almost always give the impression of being on their last legs. Images abound of antique steam locomotives struggling against the onslaught of the ubiquitous lorry as the run-down networks eke out the last years of a precarious existence. Not so in Queensland, where the extensive 2ft gauge sugar cane networks are in fine fettle. Remarkably, some sugar companies are busy building new lines to standards that would put some major networks to shame.

Travel around the Mackay region, and you are certain to find cane railways that are well used and in excellent condition. They are known locally as ’tramways’, but in many cases they are equipped to the standards of a modern main line. Some feature pre-stressed concrete bridges over river creeks, while track laid with deep ballast, concrete sleepers and Pandrol fastenings is quite common. This means that modern maintenance methods and equipment can be used.

The sugar cane harvest in Queensland between June and December is an intermodal operation. Freshly cut cane is loaded into bins carried on lorries or trailers towed by tractors. Each bin is in fact a two-axle rail wagon, which is secured on rails mounted on the trailer or lorry for the trip to the nearest railhead. This usually consists simply of a siding where the rails at one end are angled up to meet the rails on the back of the trailer. The rear of the trailer or lorry is backed up to the angled rails and then raised at the front. Gravity carries the bins on to the siding.

The bins are then marshalled into trains and hauled to the mill. Here the wagons are unloaded by rotary tipplers without the bins being uncoupled.

The bins have no brakes, and longer trains are sometimes equipped with an unmanned remote controlled brake tender at the rear. Traction is provided by a variety of diesel locomotives, some of which were acquired second-hand from QR and regauged.

The cane networks frequently intersect QR’s North Coast line, usually on the level with flat crossings. These are protected by signsals on the main line that are worked by the cane train crews, but they are not interlocked with QR’s own signalling, and QR drivers are constantly on the watch for cane trains ’making a run for it’.

An ingenious alternative to a flat crossing has been developed by Mackay Sugar Co and QR. It consists of a ’drawbridge’, with the cane line’s rails carried on supports protruding just above the QR track so that there is no break in the 1067mm gauge rails. A prototype has been installed at Balberra near Sarina to the southwest of Mackay.

An approaching cane train triggers a check on the status of track circuits on the QR line. If this is unoccupied, the protecting signals on the QR route are set to danger and the drawbridge ’gates’ formed of the 2ft gauge rails are then lowered into position. Once the cane train has passed, the gates are automatically raised and the main line signals reset. Both sets of rails are fastened with Pandrol clips. o

CAPTION: Prestressed concrete bridge over Rocky Dam creek on a recently laid 2ft gauge line forming part of the 1300 route-km CSR sugar cane network

CAPTION: Left: Prototype ’drawbridge’ crossing for 2ft gauge cane trains installed at Balberra, 943 km north of Brisbane on QR’s North Coast line

Below: Plasser & Theurer’s KMX12T tamping, levelling and lining machine enables engineers to provide good quality track