The XXL generation of cranes

By Heinz-Gert Kessel22 December 2021

A red giant towering over the MAN Wolffkran factory in Heilbronn, Germany in September 2000 signalled a significant new entrant to the 400 tonne-metre top slewing tower crane class. Heinz Gert-Kessel was invited to inspect the unit for International Cranes

At the end of September 2000, MAN Wolffkran unveiled its new flagship, the 9025 FL, with a full 90 metre jib, undoubtedly the longest saddle jib crane in its class. Around 100 distributors and customers from Germany and the rest of Europe turned up to inspect the new model.

The Wolff 9025FL is a landmark on the Heilbronn skyline with its 90 metre jib

Frank Bernhard, sales director at MAN Wolffkran explains that the company’s new XXL-class cranes, which includes the new 9025FL, will incorporate a ‘modular concept’. As a result of this, he says, there are two different versions of the 9025FL available, a ‘lifting crane’ that can handle load moments up to 630 tonne-metres and ‘reaching crane’ that can extend out to 90 metres. MAN Wolffkran, in common with other manufacturers, says it has noticed a grow­ing rental market for large saddle jib cranes around 400 tonne-metres.

The roots of the new 9025FL, which has a capacity of 20 tonnes and which will handle 2.5 tonnes at its 90 metre jib end, can be traced back to the well-known WK500SEL. The WK500SEL was a 540 tonne-metre crane developed in the middle of the 1970s. It was modernised in 1986 when the company unveiled the WK532SL, a 588 tonne-metre unit that offered a capacity of 30 tonnes, but restricted jib lengths to 60 metres. This machine was ideally suited to heavy steel erection.

The slewing platform of the new Wolff 6017FL

In 1994, Wolff seemed an order for a long jib version of the unit which led to the development of the 8036SL; a standard WK523SEL fitted with an 85 metre jib firom the lightweight low profile 7031FL. This model had a maximum capacity of 12 tonnes and could handle 3.6 tonnes at its jib end.

The first of the new 9025FL models will be delivered to Belgium-based Van De Weghe. Although the roots of the new model can be traced back to earlier units from MAN, the crane itself is a completely new design that offers a number of inter­esting irmovations.

All drives, including the slewing, are Wolff’s own ‘FU’ drive system, which it says offers smooth and economical oper­ations. Liebherr’s equivalent system combines frequency converter control with a two-speed transmission to increase the speed adjustment ratio from 1:4 to 1:7. The MAN Wolffkran sys­tem differs in that the FU drive features triangle coiling switching to reduce start-up currents while also achieving high hook speeds. When compared with the Liebherr 500HC 20, the new Wolff 9025FL will reach 125 metres per minute with its standard 75 kilowatt hoist, while Liebherr has to install a 110 kilowatt hoist  to achieve the same speed. It is worth bear­ing in mind, however, that Liebherr is likely to have a new EC-H model in the 500 tonne metre class on show at the Bauma exhibition in Munich, Germany next year, and this is likely to feature an improved hoist.

The red coloured anchor studs can be reused in the new Wolff foundation system

Another new feature on the 9025FL is the CCplus system, similar to the ‘Plus’ reserve capacity release system on the Liebherr Litronic EC-H range which increases available load moment by 20 per cent at the flick of a switch. Wolff, however, claims two major differences between its CCplus and Liebherr’s equivalent. First, it says, when entering the ‘plus’ load moment mode the operator does not need to stop operations to switch
mode – it can be done with the load in motion. Second, the CCplus is included on every unit at no extra cost (on the Liebherr it depends on whether the user is paying for the Litronic option). 

Rental target

With rental companies growing and their requirements increasingly coming into new designs, it is no surprise the 9025FL can be broken down into container-sized components to reduce transport costs. The erection of the new model has also been simplified so the heaviest component to be lifted is 11 tonnes. This compares with a heaviest compo­nent of 15.95 tonnes on the Liebherr 500HC 20.

Instead of the massive 2.5 metre TV25 tower sections used on the WK523SL, the 9025FL can be rigged on the smaller two-metre wide TV20 tower sections, fom of which offer a height under hook of 45.5 metres. If using the TV25 sections, height under hook can be increased to 59 metres. By comparison, the Liebherr 500HC 20 will reach heights of up to 80.6 metres on the sa111e tower system, although the Wolff can get higher if it uses the larger 3.3 metre TV33 sections.

Most companies will now offer a range of jib lengths beyond 40 metres. For narrow site conditions the 9025FL will even have a 30 metre jib available. The counterjib also varies from 16.6 to 26.6 metres, depending on the main jib length, thus ensuring flexibility on congested sites. This is missing on some other ranges including the Terex Peiner SK range where only two lengths with about three metres difference are offered.

Like the Rotec TC2500, a top slewing giant with a 100 metre jib, the Wolff 9025FL has three A-frames supporting the jib pendants. Although a 90 metre jib is not unique (Liebherr, for instance, had one on the 3150 HC deliv­ered to Thyssen Stahl in Germany in 1987), it is unique in the 400 to 500 tonne-metre class. It is likely that the 9025FL will be popular on construction sites where a large area needs to be covered by a 400 to 500 tonne-metre crane. It will offer a much cheaper alternative to an oversized tower crane in the 2,000 to 3,000 tonne-metre class. Its capac­ity of 20 tonnes at 24.4 metres in two fall oper­ation surpasses the Wolff8036SL, although the Liebherr 500HC20 will lift the same load at 32.4 metres. Over increasing jib lengths, however, the Wolff 9025FL catches up and even performs slightly better. At an 80 metre radius fom tonnes can be lifted instead of the 3.2 tonnes with the Liebherr 500HC 20.

The Liebherr 500HC 40, the well-proven 40 tonne version of the 500 tonne-metre crane, working at an airport extension in Dusseldorf

The Wolff 9025FL will certainly appeal to the core tower crane market, Germany, and also the surrounding European countries. What will be inter­esting to see is how the competition reacts when the latest developments in the 500 tonne-metre cranes are unveiled at Bauma next year.

Although the 9025FL dominated the open day event another newcomer from the Wolff range was also unveiled. Following the recent trend for 60 metre jibs in the 100 to 200-tonne metre class, MAN Wolffkran presented the 6017FL, a 140 tonne-metre saddle jib which fits nicely between its 125 tonne-metre 5520FL and its 200 tonne-metre 6522FL.

As many components as possible have been taken from the well-established 5520FL, Wolff’s best-selling unit ever. A number of additional features are included, for example, a 37 kilowatt hoist, a second five kilowatt slewing drive, a 60 metre jib and the CCplus feature for extra capacity. With a capacity of two tonnes at the 60 metre jib end, the manufac­turer claims it has a leading position in the 140 tonne-metre class. The maximum load of six tonnes can be lifted at 2 metres further out than the 5520FL. By combining 2 metre and 2.5 metre mast sections, a respectable 74 metre free standing height under hook can be attained. First of the new models will go to local German company Wilbert Kranservice.

In addition to the new cranes, MAN Wolffkran presented new foundation anchors which allow the multiple use of expensive anchor studs. Re-using the new foundation system can reduce costs by about 65 %, says Wolff, as the lost material in the concrete blocks is dramatically reduced.

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