There is a number of factors that influence the deviation of rails from parallelism or their premature wear, for example:
- vibration loads;
- errors that were made during the installation process;
- condition of the crane travelling mechanism;
- sagging of supporting columns due to environmental factors;
- operation of the crane track with excess of the design loading (crane overload);
- lack of preventive repairs, including control and fitting of bolted joints;
- exceeding the operation time of the crane track, installation of additional lifting machines in the span without preliminary calculations.
Levelling (geodetic survey) of crane tracks is carried out to estimate the volume of repair work. The data obtained helps determine the horizontal and vertical deviations. The actual number of "points" that require adjustment and repair is determined.
The height crane track alignment can be performed in two ways:
- By raising/lowering the rail;
- By raising/lowering the crane beam with a rail attached to it.
Raising is carried out by means of the backing material - metal plates with a thickness of 5 - 30 mm.
The alignment method is chosen based on the degree of wear and the type of the crane track, in the case of the overrunning rail - the type of crane girders: they can be metal and reinforced concrete.
When assessing the cost and timing of the crane track repair, the main indicators are considered:
- type of crane track (underrunning, overrunning or ground);
- length of the crane track;
- height of the crane track location and access to it;
- the number of points requiring aligning;
- type of joints (risers, studs, etc.);
- whether joints of the crane tracks will be replaced (risers, clamps, bolts, etc.).
Therefore, we ask you to provide, in addition to the executive survey of the crane track, which should be carried out no earlier than six months prior to the works, photographs of the track components and joints, information about the lifting mechanisms installed along this track, access platforms, the schedule of the lifting mechanisms shutoffs. The most effective way will be a visit of a specialist to the work site.
The alignment works are carried out in several stages:
- Primary geodetic survey (levelling) of the track to estimate the scopes.
- Repair works.
- Geodesic survey of the track to assess the results.
- Issuance of the Acceptance and Commissioning Certificate of the ground/overhead crane track.
The MKS specialists have enormous experience in aligning of both overhead, supporting and ground types of crane tracks. When ordering alignment from our company, you may rest assured of the accuracy of determination, meeting of deadlines and results of work. For consultation, calculation of cost and estimation of the work amount, contact our specialists in any convenient way given in the contact section (hyperlink).