On home ground21 April 2021
Self-erecting tower cranes have established themselves as the lifting machinery of choice for housebuilding in Europe. Julian Champkin looks at their advantages.
Self-erecting cranes are a usual sight when driving around parts of Europe. You will occasionally see them working on infrastructure projects, but predominantly you will see them performing lifts for the construction of houses and low-rise buildings. Certain characteristics of these machines make them ideal for housebuilding.
“The great thing about hydraulic self-erecting cranes is that they are easy, safe and fast to erect,” says Martin Gralki of Eurogru, summing up their advantages in a sentence.
“The downside is that they have lower lift heights than tower cranes.” But high-rise building is by no means the norm. The great majority of housing, for example, is of single units of low or medium rise; and this is certainly the case in Europe, where self-erectors have their heartland.
So housebuilding is a sweet spot for self-erectors. Not every self-erector, though, is the same. Montarent, of the Netherlands, is specialised on this crane type. Joint founder and owner Richard Blokker takes us through the basics: “You have to divide self-erecting cranes in three different types. There are the hydraulic folding self-erecting tower cranes, there are the ones with a telescopic tower like the K-series from Liebherr, and there are truck mounted mobile tower cranes, such as Spierings make.
The telescopic tower types are quite rare now, at least in the Netherlands. But there is still a demand for self-erecting tower cranes here; in the last few years the market for the trailer-mounted versions for housebuilding projects has been increasing.
“Self-erectors have the advantage of being fully electric, so there is no pollution or noise.
They almost all have remote control, and on confined building sites they have more reach than do telehandlers. On such sites mobile telescopic cranes have the further disadvantage that they cannot be set up as close to a building as a self-erecting tower crane; they need more ground-space, and when they are set up they have less reach. That is one reason that the self-erecting tower crane has taken a vast share in the construction industry in the Netherlands at the expense of mobile telescopic cranes.”
In the past, self-erectors were constrained by limited lifting heights. That changed, says Blokker, just recently: “A new trend was introduced at Bauma 2019 by Potain with their Hup series of self-erectors with greater lifting height. For housebuilding, self-erectors now have enough reach and height for all the tasks that are usually needed. Only occasional loads exceed their maximum capacity, and for those a mobile telescopic crane is commonly used.”
Montarent is offering a full line of mobile self-erecting tower cranes on hire and for sale both new and used. “We specialise in the self-propelled version of the self-erecting tower crane. Most popular is our Montalift M21 4WDS self-propelled tower crane with 26m jib. It is mainly used on house renovation projects, cladding work and mounting solar panels.”
“Self-erecting cranes are very popular in Europe,” says Dominique Leullier, marketing director, Europe, for Manitowoc Cranes, makers of Potain tower cranes. “In terms of units, the European market represents the majority of the volume sold worldwide. The European way commonly is to build single houses up to mid-size buildings, of around seven stories, and that is appropriate for construction with self-erectors.” Both the height, the capacity and the reach of a self-erector can cover the whole of such projects.
Prefabrication, too, is a growing trend in housing, both with wooden pre-formed panels and, increasingly, using concrete units as well; here, too, self-erectors can be ideal. “Even if prefab parts get heavier and heavier, the range of self-erectors is evolving also in the direction of stronger cranes with improved load curves,” says Leullier.
Transport also is evolving: axles can deliver 25km/hr or 80km/ hr legal road speeds in Europe. “In addition to the standard self-erecting cranes, we see an increasing interest is self-erectors with integrated transport axles. This range is called by Potain the ‘M’ range, ‘M’ standing for mobility. Such cranes give considerably improved mobility on site, and between sites, from one to the next.”
“The type of lifting device you will need on a construction site depends strongly on the construction site itself, for example whether it is congested or not, and on the type and weight of the loads you will have to lift,” he says. “Selferectors will find their benefit when mobility on site is needed and when they can carry out the same tasks as a small top-slewing crane, as their transport cost and the time needed for erection are much lower. Their limitations compared to top-slewing is their smaller capacity in terms of maximum load, load curve and height under hook.
"Other lifting devices such as truck-mounted cranes or telehandlers will also have their own preferred job site configurations – as, for example, when the site is flat and the vehicles can move around. An inconvenience of those mobile lifters, though, is that you possibly destroy the area you drive on; you may regularly have to move your equipment around the site, which increases potential safety issues. A tower or a self-erecting crane on the other hand can very often cover all areas of the site from a single position and does not damage the ground around it. They can also be erected very close to the building, whereas mobiles need to be positioned a step away from it.
"Compared to mobile cranes, the maintenance costs for self-erecting cranes are much lower as you have no filter, tyre or fuel costs. Working even in very confined areas is much more eco-friendly as you have no noise, no smoke and no fuel. For short-lasting jobs, mobile cranes may well be more economical, as they can easily and quickly move themselves on to the next site; but for jobs lasting two or three months or more the self-erector will be cheaper.
“So the ‘playground’ for such self-erecting cranes is indeed the residential homebuilding market, from the single family house up to bigger and higher residential lots. Self-erectors are as safe as top slewing cranes – safety standards are identical, as both are considered to be tower cranes. Self-erecting cranes are cheaper to buy, to transport and to maintain. The Potain self-erecting crane range goes from a jib length of 20m with max load of 1.8t up to 50m carrying 8t.”
“Fast erecting cranes compete very well with other lifting solutions,” says Hans-Martin Frech, global communications manager of Liebherr. “For single lifts of course truck-mounted, knuckleboom cranes or mobile cranes are faster to install. But they are very expensive if a longer time on site is needed.
For any duration longer than two or three weeks self-erectors are more economical; for building construction sites they are now the first choice. They are faster and more economical to install, and capacities of fast-erecting cranes have been growing in recent years as well: they are now competitive with a small top-slewing crane.
Self-erecting cranes are becoming bigger and stronger. Most housing construction projects in Europe can be covered by self-erecting cranes. A mid-size self-erector can reach a hook height up to 40m. With that you can cover houses up to ten stories. In comparison with a self-slewer you need less trucking for transportation, and for the erection process you won’t need an expensive mobile crane.
“Some years ago it was common to install very small top-slewing cranes, of 40-50m jib length, for such projects. But as self-erecting cranes have become more and more powerful this segment has now been almost entirely replaced by big self-erectors.
“And there is certainly a trend for higher capacities in selferectors. The Liebherr 125 K, which we introduced at Bauma in 2019, is the largest fast-erector in its class. It has a radius of up to 55m with a slewing radius of 3.2m, and it is available with an axle system that allows towing at 80km/ hr. For smaller projects our L1 series has jib lengths of up to 30m for single family houses. The HM series, designed for carpenters and roofers, are smaller mobile self-erecting cranes on fixed mounted transport axles; and the K series, which is our most popular, are rope-mounted self-erectors with variable hook heights and a flexible jib configuration which makes it adaptable to many different construction projects. Germany, Switzerland, Austria and France are the most popular markets for self-erecting cranes.”
“The self-erector is still very popular thanks to its versatility on the job site, from small and quick project to medium and longer job sites. More and more construction companies are looking at self-erecting cranes as a more efficient product. It is a good compromise between transportability, hook height, capacity and job site planning,” says Nicola Castenetto business development manager, Tower Cranes at Terex.
“It is a matter of capacity and hook height, but selferectors are definitely a good choice when building a house or expanding a warehouse or finding an economical fit to specific development projects.
“Large self-erecting cranes are a big portion of the market, but small cranes are still very common especially where there are space constrains and the capacity needed is not really demanding. We are seeing in fact a rise in demand for small and mediumsize self-erectors. Clearly we need to tailor investment on the areas where demand is, which is why we recently launched our new Terex self-erecting CSE crane series. The first two models are the CSE 30—30m jib length and 4.4t capacity—and the CSE 32, with the same capacity but longer jib. This year two additional new models will be extending the range; we aim to cover the entire market.”
FMGru is based in Emilia- Romagna in northern Italy.
“Nowadays our company is widening our range of self-erecting cranes,” says Chiara Faverzani, of their sales department. “We are introducing new models in order to satisfy all job site needs.
They have different heights and load capacities and are equipped with the latest technological systems. And we are developing and improving our range of self- erecting cranes with fast axles: transporting them is much easier because they are towable on semitrailers and trailers, and can move on roads at up to 80km/h.
“We think that the trend to prefabricated housing is a big factor in the increasing demand for self-erecting cranes. For example, our new K-series has the possibility of modifying the length of the jib and the height of the hook and is designed with innovative transport systems for ease of delivery. This special range was designed to simplify erection and installation in difficult and hard-to-access jobsites.
“Our RBI range of hydraulic self-erecting cranes is very fast and safe to erect and operate, with very low maintenance costs. With jibs lengths from 15 to 40m and load capacities from 1.2t to 5t it is the best solution for small house and building constructions. The steering axles with minimal radius of curvature allows them to be positioned in narrow spaces.”
FB Gru are another Italian maker, this time from Lombardy; they offer around ten models of self-erectors. “The quality that all our models share is speed of assembly” says marketing manager Alessandro Butti. “We are seeing a general increase in demand across the entire range.
At the moment our best-selling crane is the GA 727 D 80, which sells throughout Europe.
A growing trend everywhere is automated and remote digital control for such cranes but this is especially so in Italy, because there are government incentives that encourage customers to buy cranes with these technologies.”
ENG Cranes, also Italian, have in recent years diversified from self-erectors; they are now reversing that move. Monica Colangelo is in their business office. “Over the last few years ENG Cranes developed a complete range of different types of cranes, luffers, flat-tops and derricks” she says. “But recently markets have been pushing rental companies and end users to favour self-erecting cranes over traditional tower cranes on short-term sites that do not require great heights. The economic and logistic advantages are becoming more known. That’s why dealers have been asking us for a while now to return to producing the range of self-erecting cranes that we made in the past.
“ENG Cranes has therefore decided to develop a new range of self erecting cranes that includes the launch of two new models for 2021/2022. They are the ESH 48 with 36m of jib and the ESH 52 with 40m. Both feature a completely hydraulic system for erection, extreme versatility in road transport and also for transport in containers, and have performances that are far above average. And for 2022 we are also planning to introduce the ESH 132 with 48m of jib and a climbing tower to reach 40m of free-standing height and a capacity of 8t.”
Turning to Germany, Eurogru, whom we mentioned at the start, produces the E.42.10, with 42m of jib, a capacity of 1t at the tip and 4t maximum load. It comes with options of 25km/hr or 80km/hr axles and with hydraulic stabilisers.
“This makes it interesting for rental companies because it makes for faster dismantling of the axles,” says Gralki. “We also have our Eurosprint cranes, which are designed for fast construction site set-up and flexible use by roofers, carpenters, metal workers and small construction companies.
These cranes are designed as a trailer and are towed as a single unit, complete with ballast and accessories, behind the customer’s truck.”
BKL spans both German and Italian trends, being a German rental company which works closely with Italian makers Cattaneo to carefully refine the cranes for the German market. Since 1994 the company has included Cattaneo self-erector cranes in its rental fleet and is using them successfully for more than 25 years, in housing among other applications. In 2012, BKL launched the ‘BKL System Cattaneo’ as exclusive distributor for Germany and Austria. The series consists of eight types with radii ranging from 22 to 41m, hook heights of 17.3 to 31.5m and 1.8 to 5t of load.
“These are selected, designed and continually refined especially for the needs of German and Austrian customers in cooperation with the Italian manufacturer,” says head of marketing at BKL Veronika Leger. “For example, for easier handling and faster operations, all BKL System Cattaneo cranes are equipped with two-fall technology.
“The proven CM 271, a 27m crane, was upgraded in 2017. With a maximum lifting capacity increased to 2.5t the new CM 271S1 is one of the strongest cranes in its class and opens up even more application possibilities.
In 2018, we launched an extended axle system for optimum mobility to meet the traffic regulations in Germany, 25 km/h low-speed axles as well as 80 km/h high-speed axles. And they can be towed by drawbar or semi-mounted, which offers even more flexibility. And we offer various axle adapters and a hydraulic feed for the CM 271S1 to allow it also to be towed by a tractor.”
At Bauma 2019, Cattaneo and BKL unveiled the CM 415 – that year’s Bauma seems to have been particularly good for self-erectors.
“The development is in line with the trend in Germany and Austria to increasingly use larger bottom-slewing units instead of smaller top-slewing machines: the self-erector offers three hook heights up to 31.5m,” says Leger.
“Using a 20° steep angle position the maximum hook height can be increased to 42m. The 60 tonnemetre crane has a radius of up to 41m, a peak load of 1.25t and a maximum load capacity of 5t. “And a brand new self-erecting crane is expected to be available from BKL-Cattaneo at the end of 2021. The German-Italian team are improving the tried and tested CM 74S4 self-erector crane.
Its successor, the BKL System Cattaneo CM 300, will have increased maximum load capacity of three tonnes, a 30m radius and a maximum hook height of 23m.” In Europe, then, self-erectors have come of age and are a mature technology with a more-than established market and a wellsuited application. The market, and the applications, may well increase.
As Dominique Leullier of Manitowoc puts it, “We are very confident that the market will continue to grow because the performance, mobility and versatility of the new self-erectors make them more and more attractive and competitive compared to other lifting devices.”