Case study of 7.5T Crane 50M Span for Defence

REVA Case Study

Situation :

A 7.5T 50M Span crane is required for defence to be installed in a Airplane Hangar for maintenance of the aircrafts. The building is already ready.

Complication :

1. The building height has restrictions and is not sufficient  to hold a 7.5t crane of 50M span. The headroom available is too less.
2. The building is designed for a very less dead weight of the crane.
3. The way from our works at Faridabad to the site in Jammu is not suitable to transfer a 50M long girder in a single piece.

Questions :

1. How can a 7.5t 50M span crane be accomodated in the headroom available ?
2. How can crane be made of less dead load to meet the building strength requirements?
3. How can we ship the 50M long girders from our factory to the site.

Answers :

1. Headroom : Reva opted for a special design known as fish belly design for this.
   
2. 8 wheel configuration was used for the LT, so that the wheel loads could be distributed

2) Lower Dead Weight :

1. We eliminated the platform, the requirement of platform along the girder was eliminated.
   The crane girder flanges were made sufficiently wide that on this a person could easily walk through.
2. The girder design was specially done.
3. The girder diaphragms were specially designed, to have lower weights.
4. We used German make energy chain instead of festooning arrangement. The weight of these are much lesser,
   than the conventional systems.

3) Transportation Issue :

The girder was made in such a way that it could be split in 2 parts and rejoined at site.