Will self-erecting cranes replace telehandlers?

It's a hotly debated topic - will the self-erecting crane replace the telehandler? Mantis Cranes chief executive Seamus McMenamin tells Colin Sowman how he sees the future of materials handling.

"I won't condemn telehandlers but when working two floors high and above, there are more economical ways for doing things," Mantis Cranes chief executive Seamus McMenamin says. And he is quick to point out the often unrecognised benefits self erectors can have. "On the right sites, we have shown savings up to 45%," he says.

While accepting that the weekly hire cost for a self-erector can be almost double that of a telehandler, McMenamin says: "The crane will offer better site coverage and is able to deliver bricks, mortar and other material directly to where it's needed rather than setting it on a loading bay on the periphery of the building.

"This equates to a significant reduction in labour requirement and an improvement in site productivity resulting in a shorter build programme. This means the self-erector can be off-hired sooner. Savings can also be made in groundwork costs as reduced site traffic movements lower reinstatement costs."

More importantly, he says, a self-erector can enhance health and safety on site by reducing site traffic movements. "Rehandling is not only costly in both time and space, it also brings additional health and safety considerations," says McMenamin. On confined sites there is a further benefit because although the crane's footprint is similar to a tele-handler's, it doesn't move around, so there is no need for separation zones for site workers.

Long-life machinery

Furthermore, cranes are relatively long-lived pieces of machinery and Mantis's machines have a design life of 14 years (including a mid-life overhaul). Telehandlers rarely remain in a fleet for more than five years.

Many of the self-erector's benefits also apply to mobile cranes that contractors use on higher-rise sites. Although acknowledging that mobile cranes can handle materials equally as well as a self-erector, McMenamin believes his machines still have the edge.

"Quantity surveyors usually plan for mobile cranes to visit twice a week and the site lines up jobs for it. A self-erector is on site around the clock, so materials can be moved when needed. And once contractors get used to the crane being on site, it's in use most of the time as it is used for jobs they hadn't envisaged doing," says Brian Owen, who heads up Mantis's mainland operation.

Mobiles also need to be positioned some way from the building to achieve the right jib angle for the required reach. This has two effects: first, the crane may need to be positioned outside the site boundary and second, a higher-capacity crane is needed to achieve the lift at the extended reach.

Where the self-erector cannot match the mobile is with very short jobs. "Because of the cost of getting the self-erector to site, setting it up and taking it down again, mobiles are cheaper on jobs less than a six-week duration," says McMenamin.

On jobs longer than six weeks, McMenamin believes the self-erector wins out. He says that on a 14-week job one contractor made savings of 45%.

Owen says when the economy was booming many of these considerations were put on the backburner in the rush to get projects finished - but things are changing. "There are now extreme pressures on prices and contractors are looking at ways of cutting costs. We are revisiting contractors that previously turned self-erectors down."

This maybe because Mantis's TC-25, which is claimed to be the only self-contained self-erector, can be moved to site by a single truck. The 25m-reach machine has its own fifth wheel, twin-road axles, permanently mounted ballast and can be operating in an hour of arriving on site thanks to its hydraulic outriggers.

Power comes from either a 400V supply or a demountable on-board generator (which takes the weight up from 21.48t to 22.32t).

It was designed to meet the needs of housebuilders and, before erection, can be positioned (and repositioned) on a site by a dumper, a telehandler or any other machine with a towing eye. Once erected its 19m under-hook height can easily reach over a six storey dwelling and lift 750kg at full radius.

UK market

So how big is the potential UK market? McMenamin says if the UK had the same density of self-erectors per head of population as Ireland (where Mantis is market leader) it would be about 6,000 units. As the only manufacturer of self-erecting tower cranes outside the Continent, Mantis would be well positioned to benefit from any market growth. However, McMenamin says Mantis produced 48 cranes last year and couldn't satisfy a large increase in demand. "We are not going to take on the likes of Liebherr and Potain."

He puts the self-erector's lack of penetration in the UK down to the structure of plant ownership and the dominance of plant hire, which he feels makes it difficult to introduce new concepts into the market. "Traditional crane hire companies may see the self-erector as a threat and plant hirers won't buy them until contractors ask for them. But contractors won't ask for them because they haven't seen and used them on other UK sites. It's a vicious circle."

To break this cycle, Mantis has opened its own crane hire operation. "Crane hire wasn't part of the original plan," says McMenamin, adding: "But in 1999 we could only get a crane on site as a free trial and no plant hire companies wanted to take them. So we had to do it on our own.

"A rent-to-buy scheme followed but even that hasn't fully overcome the market resistance. In the UK the problem is identifying the customer, the main contractor, the subcontractor, the client or the plant hirer," he says.

That's not to say the self-erector is a panacea - get one an all your problems are solved - they are not. One pitfall that has come to light is not allowing enough space at the end of the build to allow the self-erector to be taken down. "It's expensive to have a mobile pull a self-erector off a site," says McMenamin ruefully. To avoid such problems, and to ensure the right machine is placed in the best position for the site, Mantis offers a free consultation service.

Capacity plan

It can also provide a capacity plan and by overlaying the crane's capacity/radius diagram on to the site plan, the user knows where the crane can reach and what load it can handle at any point on site. This forms the basis of a common lift plan that is eased considerably because the self-erectors' remote operation means virtually every job is line of sight.

This has further benefits as the crane operator can also be the slinger because he can stand directly next to the load. If required, the crane can be fitted with an anti-collision system, as used on full-size tower cranes, to prevent it entering pre-determined zones or oversailing.

Operating self-erectors falls into CPCS category AC63, which requires a five-day training course plus a further three days if the operator is to be certified to erect/dismantle and move the crane around the site.

"Many contractors have been reluctant to lose a worker for a week-long training course," says Mantis general manager Robert Rowlette. "That may be disappearing under the new CPCS regime, which may be more accessible to contractors."

The use of remote-control can pose potential problems as there are times when the operator has to put the control down and other site workers could think using the crane is easy and be tempted to try themselves. "There is a key switch in the remote control that locks it and the operator is supposed to keep the key with them," says Rowlette.

The manufacturer will carry out an induction when delivering a crane but this is not without its problems, as McMenamin points out. "We are supposed to induct a competent person - but who's to say that individual is competent."

However, he remains upbeat feeling the economic downturn could be the key that finally unlocks the UK market for self-erectors. And this time he could be right.