UGL Rail C44aci - Design

Design

The C44aci was designed by UGL Rail to meet a tender issued by Pacific National, who required a locomotive to match the performance of their existing 90 class units when hauling heavy coal traffic, while still having the ability to work high speed intermodal services, with the change between applications to be simple.

The existing UGL Rail Cv40-9i (NR class) locomotive design was used as a base, but with alterations including:

• Higher horsepower prime mover
• Smaller main alternator
• Enlarged radiator size now overhangs the walkway at the number 2 end to cope with the more powerful engine
• AC traction equipment allowing an increase in haulage capacity
• Addition of inline refuelling fittings
• Isolated cab for reduced noise and vibration
• A new design of fabricated bogies
• Increased use of modular construction
• Revised transition curves in the underframe to reduce the probability of fatigue cracking
• Various body and cab modifications

The NR class design had also been used as a basis for the AC traction UGL Rail C40aci used for coal haulage by QR National. This design did not meet the requirements for Pacific National due to the heavy axle load, acceptable on the heavily laid coal routes, but not on lines outside of the Hunter Region.

To reduce the weight the level of fuel carried is altered: for intermodal applications the fuel level is 7,300 litres, for coal applications that permit higher axle loads the fuel level is increased to 13,500 litres, with an intermediate fuel level of 10,750 litres also available. These limits are enforced during refuelling by a float switch in the tank, the permitted level being set by a key switch with an indication displayed in the cab if the limits are breached. The provision of inline refuelling permits the topping up of the tanks in transit from a separate tank wagon behind the locomotives.

The older GE Transportation Systems FDL series engine was chosen instead of the newer GE Evolution Series engine used in the United States, due to the greater height not fitting in the restricted Australian loading gauge, and there being no legal requirement to meet stringent Tier 2 emissions standards which drove adoption of the GEVO series elsewhere. The C44aci has one inverter per traction motor, this differs from competing Downer EDI Rail locomotives that have only one inverter per bogie. A further difference between the C44aci and the competing GT46C ACe is the lack of steering bogies to improve tracking properties and reduce the rate of wheel wear, instead fixed-frame pedestal-type bogies are used where all three axles are always held parallel.

Simulation work showed that three C44aci locomotives could equal the performance of 90 class units in heavy mode, while in intermodal mode could outperform the older NR class units by 20% on services, with the same sectional running times and in some areas a slight reduction in fuel consumed due to the increased adhesion resulting from AC traction. However the C44aci was outperformed by the comparable GT46C ACe locomotive produced by Downer EDI Rail in back-to-back trials performed by RailCorp on the steeply graded Cowan Bank.