Rigid dump trucks built in Scotland have for the past seven years played a role in keeping pace with international demand for some of the world’s lowest sulphur coal, from the Pasir coal mine in Kalimantan, Indonesia, where annual output in 2001 is set to reach 10 million tons (9 million t).
Terex Equipment, supported by its dealer, has since 1993 supplied rigid mining trucks to the Pasir mine at Batukajang Pasir, East Kalimantan, in the Indonesian part of Borneo. Following exploration in the late 1980s, the coalfield was found to contain in excess of 1,000 million tons of coal reserves. Indonesian-based opencast mining company, P.T. Kideco, began mine development in 1989 and started commercial production in 1993.
Pasir coal is particularly sought after for its extremely low sulphur (0.2 percent) and low ash (1.5 percent) content, which saves customers money by cutting desulphurisation and ash removal costs. Customers include power utilities and carbon chemical producers in Southeast Asia, Japan, Latin America and Europe.
The first consignment of Terex trucks — 23 55-ton (49.5 t) capacity 3308s — went into operation at Pasir in 1993, each having clocked between 27,000 and 33,000 operating hours. Further deliveries followed including five 85-ton (76.5 t) capacity 3311es and 18 33100s, with a 100-ton (90 t) maximum payload. More recently, in 1999, P.T. Kideco added eight 100-ton (90 t) capacity Terex TR100s to the fleet, in preparation for a rise in coal production to 7.3 million tons (6.5 million t) in 1999.
The opencast mine has been developed with 32.8-ft. (10 m) high ’benches’ dipping down on a 30-degree slope through coal seams of between 13.1 and 98.4 ft. (4 and 30 m) thickness. Working hand-in-hand with hydraulic shovels and backhoes, the Terex trucks remove overburden at a strip ratio (overburden to coal) of up to 6:1. Rock formations typically of sandstone and mudstone require blasting before the excavated overburden is loaded onto the trucks by hydraulic backhoes and face shovels with 459-cu.-ft. (13 cu m) capacity buckets.
In the initial stages of mining a seam, the trucks haul and dispose of the overburden at an adjacent waste dump, later backfilling the material into mined-out areas as mining progresses.
P.T. Kideco’s mining operations manager at the Pasir coal mine, Lee Jong Beom, said, “To meet our ever-increasing production targets we rely heavily on the performance of our equipment as well as people. Terex and Daehae have helped greatly, supplying rugged trucks with the performance and reliability to keep productivity levels high, backed by an on-the-spot parts and service team.”
To ensure maximum availability of the Terex machines, as part of the contract with P.T. Kideco, Terex has two resident service engineers, David Butterworth and Graham Harrison, based permanently at Pasir. They work alongside 30 local dealer staff on site, who fulfill the customer’s parts and afterservice warranty requirements.
Commenting on the trucks’ performance Butterworth said, “Where the trucks come into their own in this highly demanding environment is in their simplicity and maintainability. The powertrain in in the TR100s brings together the powerful 37.7-liter Cummins turbocharged diesel engine with an electronically-controlled Allison automatic transmission — remotely mounted to prevent shocks — and the rugged Terex drive axle, for enhanced performance, smooth ride and absorption of loading shocks.
“A further great feature of the trucks seen in this application is the sheer strength both of the dump bodies and rugged frames, which have both stood up tremendously to the very demanding high-volume production schedule at Kideco’s Pasir mine site.
With annual output at the Pasir coalfield expected to increase to 12 million tons (10.8 million t) by the end of 2002, Terex is hopeful that the staying power demonstrated by its Indonesian fleet will lead to a strengthening in its relationship with P.T. Kideco.