Mon June 02, 2008
Crane Equipment Guide
Manitowoc’s latest topless tower crane from Potain — the MDT 268 — is the largest crane in the redesigned MDT range. The crane has an improved reach and numerous features to simplify and speed up the erection and dismantle process. The crane is available in a J10 version with an 11-ton (9.9 t) capacity and a J12 version with a 13.2-ton (12 t) capacity.
As a topless crane with no cathead, the MDT 268 offers contractors greater space utilization on sites where multiple cranes are working or where height restrictions are an issue. The jib also can be erected section-by-section on job sites where space is limited.
David Havard, global product manager for Potain, said the MDT 268 offers flexibility on a wide range of job sites.
“The MDT 268 offers customers enhanced performance and should set new standards in ease and speed of erection,” he said. “It is well suited to city center construction. And because there are two versions with a variety of configurations, the crane can be tailored to a range of projects.”
Both versions of the MDT 268 have a 213-ft. (65 m) jib with the J10 version able to pick 2.9 tons (2.6 t) at the jib end and the J12 version able to pick 2.8 tons (2.5 t). Several additional shorter jib options are available — for greater lifting capacity — down to an 82-ft. (25 m) jib where the J10 picks 10.5 tons (9.5 t) at jib end and the J12 picks 10.3 tons (9.3 t).
The crane uses 6 ft. 6 in. by 6 ft. 6 in. (2 by 2 m) mast sections and offers a maximum free-standing height of 229 ft. (70 m) when mounted on fixing angles or maximum height of 246 ft. (75 m) when mounted on a chassis.
Both versions of the crane offer hoist options. The J10 version comes with either the 50 LVF 25 Optima winch or the 75 LVF 25 Optima. The former can offer hoist speeds of up to 315 ft. (96 m) per min. with a 1.4-ton (1.2 t) load, while the latter can reach speeds of up to 361 ft. (110 m) per min. with the same load.
For the J12 version there are three hoist options: the 50 LVF 30 Optima, the 75 LVF 30 Optima and the 100 LVF 30 Optima. The 50 LVF 30 Optima can offer hoist speeds of up to 296 ft. (90 m) per min. with a 1.7-ton (1.5 t) load. The 75 LVF 30 Optima can offer hoist speeds of up to 381 ft. (116 m) per min. with 1.7 tons on the hook. And the 100 LVF 30 Optima can offer hoist speeds of up to 531 ft. (162 m) per min. with a 1.7-ton load.
LVF Optima hoists offer productivity gains by optimizing the hoist speed in relation to the load on the hook. The hoists also offer costs savings because smaller generator sets can be used compared to cranes equipped with conventional hoist winches, according to the manufacturer.