First publishedon www.AggBusiness.com
Caterpillar's new 938H wheeled loader is said to offer considerably higher performance than the 938G II model it replaces. Mike Woof reports
With features more commonly seen on larger machines only, Caterpillar's 15.5tonne 938H wheeled loader is a high quality machine and is being offered worldwide. The new 938H replaces the 938G II machine and offers considerable performance improvements.
Power for the 938H is increased by 8% and comes from Caterpillar's new C6.6 diesel rated at 134kW, which features ACERT engine technology and minimises emissions as well as fuel consumption. Caterpillar's sophisticated ADEM A4 electronic controller governs the ACERT engine package, integrating the common rail fuel system and smart waste gate turbocharger.
This new engine is a 6.6litre, straight six cylinder unit with a crossflow head for additional combustion efficiency that meets the important Stage IIIA requirements for noise and exhaust emissions. To further optimise fuel consumption the machine is fitted with an auto idle system, which automatically reduces engine rpm 10 seconds after the handbrake is engaged.
The loader also has new features that improve servicing. An in-cab display gives real time machine performance, engine and diagnostic data. The hydraulic and electrical service centre offers grouped service points, with easy access from ground level to limit service downtime. Machine uptime can be increased using the Cat Product Link system, which provides two-way information flow between the machine and dealer and is standard on the new loaders.
According to Cat, the hydraulics are more efficient than on the previous 938G II. A load-sensing, variable flow hydraulic system is fitted that senses demand and adjusts flows and pressures accordingly. This smart system allows the loader to deliver full hydraulic forces at any engine speed, as well as providing faster cycle times, with low operator effort and improved fuel efficiency. Meanwhile load-sensing steering and implement flow make more power available for rimpull and loader forces without requiring the attention of the operator.
The hydraulics also allow the operator to lift a load and tilt the bucket simultaneously, further cutting cycle times. The machine is offered with buckets ranging from 2.3-3m3 in capacity as standard and can also be equipped with Cat's quick coupler system.
A specification that is not normally fitted to machines in this size class but available on the 938H is the ride control system that is installed as standard, which can significantly reduce bucket spillage when travelling at speed. This is fitted in the hydraulics of the loader arm and bucket linkage, reducing the effects of the inertia generated by the material in the bucket. Another feature offered is an optional payload indicator.
The 938H also comes with new axles and a manually controlled differential lock for the front axle as standard. Automatically controlled differential locks are offered as options for the front and rear axles, which sense when traction is lost and kick in. Both the automatic and manually applied differential locks can operate while the machine is moving, rather than requiring the operator to stop to allow them to engage as with earlier generation systems. Wheel slip can boost tyre wear significantly so this feature will help increase tyre life, an important point given the current availability issues.
The cab has large glass areas to improve visibility while the controls are designed ergonomically, to allow the operator to use the machine with less fatigue throughout a working shift.
Bucket capacity: 2.3-3m3 Operating weight: 15.5tonnes Engine: 134kW C6.6 diesel
Special features: Ride control; Load sensing hydraulics; Differential locking front axle - manual as standard and automatic available as an option