Liebherr Great Britain has recently delivered the UK’s second LH 26 CE electric drive material handler to recycling specialist Mid-UK of Sleaford, Lincolnshire. A third is to follow later this year, as part of an order for seven electric LH 26 machines for Mid-UK, who already run a Liebherr biased fleet to handle a huge variety of waste from around the country.
The use of electric power for excavators has mainly been confined to large mining excavators, but there are certain applications in the UK where the use of electrically powered machines is being championed. The waste industry has been an early adopter of this technology, with static mounted plant being electrically powered for many years.
Already operating a large fleet of Liebherr material handlers and wheeled loaders, Mid UK has been impressed with the reliability and extremely low fuel consumption of its’ existing diesel engine fleet. They were quick to order the new electrically powered 25 tonne crawler machines in a bid to reduce fuel consumption even further.
Whilst a number of Liebherr wheel loaders are used in various applications at Mid UK’s different processing plants, the fleet of crawler and wheeled material handlers operates predominantly within the confines of a building.
The nature of the waste handling industry dictates machines may sit idle for a percentage of their working day, due to processing machinery or incoming
loads being delayed for various reasons. Diesel powered handlers sit on tick-over for up to 50% of their working lives and do not represent the most cost effective operation.
This excessive idling time, coupled to the fact each machine consumes diesel whilst idling, swayed the management team at Mid UK to look at alternatives for its’ materials handling operations.
Constructed around a standard material handling variant of the company’s 24-25 tonne LH 26, the CE version sits on 2.4 metre crawler undercarriage, offering exceptional stability even when working at maximum radius across the tracks.
There is now a 110 kW electric motor in place of the diesel engine. The exhaust pipe has gone as has the diesel tank to the offside, now replaced with a large reversible fan to ensure the motor and cooling systems are kept at the lowest working temperatures at all times.
An opening panel behind the cab allows pedestrian access to the top deck, whilst the large rear panel, which traditionally accommodates the cooling pack, now houses the electrical cabinet. Weather protected to an IP55 rating, the cabinet houses the main contactors for both the undercarriage and upper structure plus the starter for the motor.
From the top working platform, the “engine” cover is simply lifted up on gas struts to give easy access to the top of the 110 kW induction drive electric motor, which achieves full power at a very low 1489 rpm.
The dedicated 400 v supply comes via a large cable affixed to the undercarriage and fed through the centre of the slew ring, and this particular machine has been equipped with enough slack in the cable to allow it to work from two operating positions – allowing a large degree of flexibility.
The hydraulically raising cab gives the operator a much improved sight-line across the working area. The Liebherr cab is almost identical to that of the standard machine apart from the addition of a small colour monitor to the operator’s right hand side.
Positioned above the standard Liebherr monitor, this additional screen displays information for the dedicated electrical system. Ample storage is included, and a generous space is available behind the air cushioned operator’s seat, while the quiet motor provides an almost noiseless working environment of 71 dB inside the cab and 100 dB in the surrounding area.
The hydraulic operations for the LH 26 CE are a mirror image of those found on a diesel machine. The joysticks with standard proportional control via 4-way mini joysticks improve functionality and increase operator comfort.
The LH 26 CE is available with a wide range of material handling boom and dipper configurations. Mid-UK has specified the GA10 attachment, which comprises a 6.1 meter straight boom and 4 meter angled stick. With this configuration a GM65, 0.6m3, 5-tine grab has been fitted, and gives the outfit a maximum reach of almost 11 meters.
The LH 26 CE’s LiDat figures show a significant reduction in the operating time compared to its’ diesel counterparts. The lack of a diesel burning motor also provides huge benefits in keeping a safe working atmosphere within the building. Far exceeding the current Tier4 final requirements, the electric handler does away with the need for expensive and complicated exhaust gas cleaning systems, therefore reducing the weight of the upper-structure.
An additional benefit, and one often associated with the waste industry, is the challenges in keeping the engine running at a safe temperature. Prone to overheating because of blocked cooling systems, material handlers of all makes are often fitted with reversible fans to clear out debris stuck to the radiator cores.
Thanks to a cooler running electrical motor, the LH 26 CE can be operated for much longer periods of time without the need to clear out the cooling pack. The reversing system on the LH 26 CE allows for particles of waste to be blown free at any time, whilst the machine is still in operation.
Mid UK’s first LH 26 CE has worked in excess of 2000 hours, and has proved to be a faultless machine providing the clean, efficient and highly productive operation required by the company. The LH 26 CE has been widely accepted by both operators and management as the way forward for the Mid UK’s operations.