This started with the production of Liebherr’s first ship-to-shore container crane in 1967. Since 1998, rubber-tyred gantry (RTG) cranes have been developed and manufactured in Killarney, with more than 130 RTGs now in operation throughout the world.
The Killarney factory was Liebherr’s first outside of Germany and was originally used to manufacture tower cranes. LCC was established as an entity in 1972 in order to specialise in the manufacture of container cranes, and since then more than 350 container cranes have rolled off its production line. The company has established itself as a lynchpin of the local community as a major employer, and has a strong relationship with the local council.
The development of LCC’s straddle carrier is part of a host of ongoing developments at the Killarney site. The factory is surrounded by a golf course, and the company has secured a deal to buy the seventh hole in order to facilitate further growth. This is part of a number of new facilities at the plant, including a new milling and boring hall currently under construction, a new manufacturing hall and a new cutting hall recently completed. These developments are valued at many tens of millions of pounds.
LCC says the straddle carrier line, designated as SC440S for models to date, complements Liebherr’s existing range of port equipment. Pat O’Leary, managing director at LCC, says the impetus for developing the straddle carrier line was from customers asking for higher reliability and performance, and wanting to know why Liebherr was not in the market.
“There was a definite opening for another manufacturer in the marketplace,” says O’Leary.
The SC440S was first developed in 2007 and has undergone extensive testing and refinements. It is capable of lifting 1-over-3 high, with an SWL of 40.6t under the Liebherr-Elme single-lift electro-hydraulic spreader. An optional twin-lift system offering a lifting capacity of 50t is also available, as is a working capacity of 1-over-2 high. With a full load, the SC440S has a lifting speed of 18m/min, while empty the lifting speed reaches 26m/min.
Side-shift and skew functions allow the operator flexibility when handling containers, with side-shift of + or – 290mm and skew at both ends of + and – 7°.
The engine is a Stage III-compliant 350kW Volvo-Penta diesel model. Driving speed is 25km/h with either a full load or empty for the 1-over-3 model, increasing to up to 30km/h for the 1-over-2 model.
LCC says one of the key benefits of the Liebherr SC440S is that it has no hydraulics on the legs or up high on the crane’s structure; a “new concept in straddle carrier hydraulics” according to LCC’s product manager, mobile, Paul Bolger.
Having the hydraulic system positioned low down on the crane means there are shorter hose links, increasing steering response. It has also used proven crane technology in the design of the hoist drive and brake system. This has helped LCC develop a “very reliable straddle carrier”, Bolger says. “This is a little more expensive, but is a better solution.”
The design also allows ground-level engine start-up, which provides ample opportunity for the straddle carrier to warm up in cold conditions while the operator climbs the 14m legs to the front-mounted cab.
The unique placement of the hydraulics is coupled with an electronic drive-by-wire steering and braking system, which Bolger says is unique on the market.
LCC says it offers a much cleaner design with better accessibility and reduced maintenance along with the ability to adjust to operators’ steering and braking sensitivity. It ensures a small turning circle using four individually steered axles. Other benefits of the SC440S steering system include shock relief valves for impact protection and continuous automatic wheel alignment correction. The suspension system deployed on the SC440S is taken from equipment used in the mining industry.
Only AC electric inverter drives are used for travel, hoist and auxiliary functions on the straddle carrier and they are optimised for bi-directional variable speed movement. The hoist unit employs 24mm rope, with a simple reeving layout to help improve rope life. Regenerative braking is included in the SC440S’s system, with the energy returned direct to the electric rope winch hoist, and vice versa during hoist lowering to assist in travel acceleration.
Bolger says operators have also responded well to the ability to set automatic height positions of the load, which allows them to work faster and more efficiently, and not waste time manually raising and lowering loads on the quay or from a truck.
Overall, LCC says these developments will reduce the maintenance costs of the SC440S straddle carrier, as well as reduce its environmental impact by lowering fuel and oil consumption, by as much as 30% compared to some other straddle carriers LCC suggests. For instance, Bolger says, the straddle carrier tyres have exceeded 8,000hrs of testing, although their life expectancy will depend on individual port environments and tyre specifications.
The SC440S shown to a select group of journalists at the Killarney site is LCC’s third model, and has since been delivered to Belfast Container Terminal to join the first two machines which have been in full operation since commissioning.
The current lead time for the SC440S is four to six months, “as it is not an off-the-shelf product”, says Bolger. Bolger adds LCC has sensible expectations for its first straddle carrier, with predictions for how 2010 will develop difficult. However, he says, LCC would be happy with sales of 25 straddle carriers or more this year.
