Cities have very little space. Cities have narrow roads. Cities have tall buildings. City authorities don’t like noise. City authorities don’t like emissions. City authorities don’t like vehicles that block traffic whilst working or even while travelling to their worksite. City authorities, however, still want buildings to be constructed, maintained and repaired. And they want cranes that are able to do those tasks whilst complying with all the above requirements. In short, cities might not want the impossible but they do want an awful lot! Enter the city crane and its growing significance.

To the uninitiated a city crane might look like a smaller, more compact version of an all-terrain. It is compact for a reason: so it can fit into those little spaces. To avoid the perpetual throb of diesel whilst at work city cranes are prime candidates for electric power (now that technology is making this a practical possibility). Electric power, of course, relieves the city of the stench of dirty diesel fumes and the thrum of the diesel engine; hence the design of the modern City Crane – a concept that is now advancing on all fronts.

In our praise of the adaptiveness of the city crane, however, we’ve neglected to address the ‘tall buildings’ bit – a key feature of city centres. A city crane actually cannot reach the top of a very tall building. For that, of course, you need a tower crane. But tower cranes are expensive to install and operate. They need lots of large lorries to deliver them and they stay on-site for months at a time. For a medium-rise project, or for a job that takes only a day or two (or even a week), to erect a tower crane when you don’t have to would be insane.

So the city crane is in demand. And new versions of them are in development and being launched. Liebherr, for example, has its LTC 1350 – 3.1E hybrid, with an elevating cab, which was launched in October last year.

The ‘E’ stands for electric. The crane is essentially its 1050-3.1 conventional drive city crane but now with an electric motor attached for lifting. The internal combustion engine is still used for driving to the site but, once on site, the electric motor can be powered by cable from whatever supply is locally available.

Like its non-electric parent it is compact – just 2.55 metres wide – so it can manoeuvre into small spaces. It can carry all its ballast on board, plus its double folding jib and hook block, so no back-up truck is needed (which would only add to the congestion in restricted city streets). The electric motor can deliver 72kW of power.

UK-based crane and lifting company Ainscough has taken delivery of the first LTC 1050- 3.1E in the UK; it also has a second due for imminent delivery – which it ordered even before having tried out the first. The company has a long-standing and close relationship with Liebherr. “We have quarterly meetings where we discuss crane requirements and design,” says Peter Gibbs, CEO at Ainscough. The first LTC 1050-3.1E is currently based at Ainscough’s Bristol depot.

“We see a lot of opportunity for them,” Gibbs continues. “It's a city crane so it's a little bit narrower, to get in and out of places that others wouldn't fit, and its lifting power is electric. This is key as our company is carbon neutral. We are the first mobile crane company in the world to achieve this. We were formally audited as of October 2023 ¬– so we’ve maintained this status for over a year now.

“The LTC 1050-3.1E is another step along this sustainability road. Our first machine has already completed a job in Bristol (see box). Since it is emissions-free, with far less noise, we see a lot of opportunity for it working inside buildings, getting into warehouses and so on.

“In addition, EDF has recently put the roof on the reactor building for Hinckley Point 3 nuclear power station, which is near to where the crane is based, so work inside there would also be a very suitable project for it. The second machine is destined for London, and there are clients there for whom noise abatement is as important as anything else.”

MOBILITY MATTERS

There are now large crawler cranes that are entirely powered by battery. The city crane, however, is a plug-in hybrid with both a diesel engine and an electric motor but with no battery on board. It might seem strange that a heavy crawler can be battery-only while a lighter city crane cannot. Gibbs explains why. “It’s about weight,” he says. “Crawlers get carried to their job site on a flatbed truck and only move slowly for short distances around the site. Mobiles and city cranes, however, drive themselves – often for miles at up to 40 km an hour on public roads and motorways. The battery needed for that would be massive and would add huge weight to the crane on the road. This would be inefficient and demand yet more power capacity from the battery… so it is very deliberate that the city crane is a plug-in.

“On the road we power all our cranes on hydro-treated vegetable oil (HVO), aka ‘renewable diesel’ rather than fossil-derived diesel, as part of our zero-carbon status. It is on-site that the electric motor comes into its own.”

Most city job sites have access to grid electricity… but some do not. Even at those that do the grid power available may be insufficient for peak crane demand – such as lifting a large load at speed, for example. The cables snaking across the ground to your city crane may also well be a safety hazard. Liebherr and Ainscough have thought of that. The LTC 1350 3.1E can be battery-powered, after all; it’s just that the battery is not on board. A large, free-standing battery pack – Liebherr calls it the Liduro – can be delivered to the site, set down next to the crane operating area, and plugged into it; only a short length of cable, right next to the crane, is needed.

“The battery weighs 1.3 tonnes,” says Tony Gribble, general manager aftersales of LWE mobile and crawler cranes at Liebherr GB. “In Europe the crane itself can tow the battery to the site. UK regulations, however, don’t allow that so another truck delivers it. It can supply power at 32 kW, 64 kW, or 128 kW. At 128kW the crane speed is almost the same as when it is operating from the engine – which is impressive. When it is at 32 kW the crane’s movements are noticeably slower although the battery will last a longer time. The battery can be tricklecharged at the site, drawing a small but constant current from the grid without overloading it, which can sometimes be a good solution.”

SMALL BUT SWEET

Kato has been a pioneer of the city crane and last year it brought out a new model: the 13-tonne CR-130Rv. The crane is now available in Europe through Kato’s European distributor Rivertek Services. Ivan Bolster is Rivertek’s operations manager. “The CR-130RV has proven hugely popular throughout a range of industries in Europe,” he says. “It is one of the smallest mobile cranes available on the European market, and crane rental companies can earn very decent revenues with it, so it is very popular with rental companies in particular.

“When it is not busy on tight confined jobs customers also use the CR-130Rv for timber house construction or inside warehouses and manufacturing facilities. It’s also popular for areas where road access is tight as the CR-130Rv is only 1.89 metres wide.”

An alternative for narrow and hard-to -access sites is the spider crane. Bolster, however, says the city crane can prove the better solution. “The mobile element to the CR-130Rv gives it an advantage over the spider crane category,” he explains. “This is because the CR-130Rv can travel from job to job under its own power; unlike the spiders it does not need a truck to transport it.”

Hence if offers a saving in money and also in inner-city congestion. Because it has a gross weight of less than 14,000kg the CR-130Rv can be much less invasive in those environments and much less likely to cause surface or ground damage.

“Our CR-130Rv is fitted with the latest Stage V compliant engine but we also offer a power pack as an optional extra which can be quickly installed to the rear of the crane,” Bolster continues. “This gives customers the option of a plug-in version. It has a fully powered 24m main boom and, as standard, two winches, a hydraulic fly jib, a three-tonne searcher hook and remote outrigger set-up with auto self-levelling.

“The CR-130Tv has a big brother in the form of the 25-tonne Kato CR-250Rv, which is also available in Europe, and is as equally as popular as the CR-130Rv.

“It has all of the features of the CR-130Rv plus, for example, an aerial mounting for the fly jib which allows it to be fitted in a really small working area. The jib telescopes and offsets hydraulically. As with all Kato city cranes main booms are fully powered with full lifting capacities while telescoping in and out.”

So the city has the crane that suits it, which should leave both city authorities and crane operators happy. Its electric evolution represents a pivotal advancement in the lifting industry, especially in urban environments where space is at a premium and stringent regulations regarding emissions and noise are enforced.

These innovative new machines embody the marriage of compact design with ecofriendly electric power, offering unprecedented versatility and efficiency. As the industry increasingly embraces sustainability as a core value, the city crane paves the way for cleaner and quieter operations in city centres while their flexibility, particularly with the development of battery packs, ensures adaptability to diverse job sites, from construction projects next to schools and hospitals to indoor installations, thus addressing the multifaceted needs of both city authorities and crane operators.

With ongoing advancements and increasing demand, the future of city cranes appears promising, poised to revolutionise urban construction practices while minimising environmental impact and maximising productivity.

TADANO IN DEMAND

The Schmidbauer crane rental and haulage group, headquartered in Munich, Germany, ordered no fewer than six Tadano city cranes last year. “The extremely compact AC 3.045-1 City is simply our crane of choice when it comes to projects in urban areas and tight work sites,” reports managing director Dr. Mitja Schimek.

His colleague Christian Schlagbauer, manager at the Ingolstadt branch, also has words of praise for the compact design and the resulting maneuverability behind the AC 3.045-1 City. “On top of that the crane generally has extraordinary lifting capacities and especially when telescoping under load,” he said. “This makes it unbeatable from our perspective when it comes to indoor projects.”

Schmidbauer ordered all six AC 3.045-1 City units with an e-Pack prep package for zero-emission crane operation. The cranes can make full use of the electric power even in cleanrooms. This expands the range of applications for a crane that is already extremely versatile but is also crucial for the company’s green future.

Meanwhile Dutch industrial service provider Convoi is also familiar with the advantages behind the Tadano cranes: “We’ve had AC 40 City cranes at work since 1997, and they have proven time and time again that they are the perfect cranes for machinery relocation projects. In a nutshell, they are compact, powerful, and extremely maneuverable above all, which makes them simply unbeatable when it comes to work in small spaces. And now, with the new AC 3.045-1 City, we’re giving it a state-of-theart sibling,” explains Convoi site supervisor Remco Scheffers while picking up his new crane in Lauf, where it was handed over by Tadano Sales Manager Richard Beenen.

Convoi ordered the Tadano AC 3.045- 1 City with comprehensive equipment, including a runner, cameras, and remote control. “The crane will be operated by Convoi Switzerland to extend its crane fleet and, more specifically, the AC 3.045-1 will be used for new installations,” reports Remco Scheffers, who goes on to mention another advantage behind the AC 3.045-1 City: “Its practical axle loads and compact dimensions make it particularly easy to get travel permits for it, which makes the compact Tadano City crane even more costeffective for us.”

EXPLORING ALTERNATIVES: FIRST JOB FOR AINSCOUGH'S LTC 1050-3.1E

Ainscough Crane Hire’s new LTC 1050-3.1E crane, the first of its type in the country, has undertaken its first lifts since being added to the company’s fleet.

Ainscough was appointed by UK infrastructure services, construction and property development company Kier to deliver lifts as part of its £28m redevelopment of The Crescent Centre, an office building at Temple Quay in Bristol. Designed by architect Buckley Gray Yeoman, Kier’s work will double the total floor space from less than 50,000 sq. ft to 101,000 sq. ft, with floor plates of up to 18,000 sq. ft.

The redevelopment includes a new two-storey façade with amenity space on the ground floor. There will be a one-storey rooftop extension and the addition of three private roof terraces. Ainscough was appointed to lift ribbon extension cable, green roof equipment to the building’s roof, as well as insulation and air duct sections.

The LTC 1050-3.1E crane was chosen for the job due to the restricted space on offer in the city centre location. Low noise and emissions were also key factors, allowing the crane to work where a conventional crane could not.

Chris Willis, manager of Ainscough’s Bristol depot said: “All of the capabilities that make the LTC 1050-3.1E stand out – its flexibility and its environmental credentials – were on show over the course of this two-day operation.”

Jason Taylor, regional director at Kier Construction Western and Wales, said: “Having this hybrid crane working on our site provides a valuable opportunity to explore alternatives to fully dieselpowered options.”