Kobelco 7250S Lattice Crawler Crane

Presented here is the Kobelco 7250S in 1:50th scale whicht shares the same base undercarriage castings and upper body castings as the previously released Kobelco CKE2500G. Out of the box, the crane can be built in two configurations, one with the tower jib fitted, and one as a standard lift crane with boom tip.

All the parts are presented in three polystyrene trays with a comprehensive assembly guide providing step-by-step instructions which are very easy to follow, with all the small parts located in sealable bags, complete with printed labels identifying the parts.

The undercarriage frame has detachable track frames, with the self rigging system fully modelled, consisting of four rotating arms with pivoting, height adjustable jacks allowing self assembly of the track frames which bolt into place.

There are locations on the undercarriage to connect a pair of ballast blocks which lock into place with small pins. The design of the ballast segments is one of the many differences between versions. The undercarriage is finished with four self-fit access ladders which connect to the inner corners of the track frames.

The cabin has a finished interior, complete with the driver’s seat and controls that are visible through the clear glazed windows, complete with printed window seals and tiny warning labels. A ridged debris protection screen covers the roof window with integrated grab rail and rear view mirrors fitted to the frame, screen wipers fixed to the front window and a slotted platform in front of the cabin.

The rear of the upper body casting has a different configuration, with three full sized counterweight plates and two additional side plates on each side. The base plate pins into position once the shipping support bars have been removed and this is another nice touch, with the A-frame pulley system fully rigged out of the box and cleverly taped up to prevent the ropes slipping off the pulleys.

The operational design for the main boom is another of the differences with a more conventional look having a fixed A-frame with ropes fitted to the spreader that connects via rope pennant lines to the top of the main boom. The collector has a choice of how many extension mast sections to fit from the five 9 metre and one 6 metre sections included in the box.

Once the main boom is connected, there is unfortunately not enough rope fitted to the rear winch to allow the mast to be fully lowered which is a little disappointing, considering the earlier CKE version allowed a full range of adjustment.

Another option at this stage is to configure the crane for standard lifting, or to fit the included tower jib. The tower cap fits to the end of the main mast, using tiny nuts and bolts to secure the connection. To this, the strut assembly is fitted with more rope pennant lines used to connect between the struts and the jib spreader.

The jib can be built in different lengths, with one 6 metre section and two 3.1 metre sections provided in the box. Once everything is assembled, the remaining rope for the jib control needs to be wound onto the rear-most main winch and once tensioned, the jib can achieve a full range of movement, folding down to rest alongside the main mast or rising to full height. The set even comes with plastic locking bars which clip onto the main and jib sections, using a pin to secure them together.

Once the configuration is complete, a number of detailing parts need to be added including metal walkways on both sides of the upper carriage incorporating safety railings with additional railings around the upper body where two side access ladders need fitting.

Winch operation is by inserting a winding key into the winch housings and these are cleverly hidden behind detachable panels with good surface detailing of the winch housings showing all the fixing bolts. The winches have an in-built braking system and rotate smoothly. Three different hook blocks are included in the box, a 70t and 35t conventional hook and a ball hook with a H-section metal bar with rope included to use as a load to keep the main lifting rope lines taut.

The railings on the side platforms are a little bent, but other than that, the model went together surprisingly well considering the complexity with no other build problems encountered. The addition of the tower jib gives the model a more impressive look over the original CKE version in my opinion and the use of metal for most of the parts is great to see.