Introduction
Rigtech have been inspecting cranes for over ten years, both during the course of our rig condition evaluation and as a specialized inspection in it’s own right.
The company is recognized by a number of flag states as an independent crane inspectorate including Vanuatu, the Marshall Islands and Liberia.
Our crane inspection training course is one of the few dedicated to the inspection of offshore cranes. The course will be accredited by the Institute of Marine Engineering Science and Technology (pending), which is an internationally recognized professional body. (The following is a short extract from the course).
Whether Hydraulic or Electric, the drive motors will drive the hoists through some form of gearbox. Primary checks for our inspection will include;
- Checking the gearbox internal components for wear and damage.
- Checking sprockets, gears and internal spline drivers where possible.
- Checking the gearbox hold down bolts are securely fastened and corrossion free.
- Verify that sampling of the gearbox oil has been conducted and review analysis results.
We will verify whether the gearboxes have been internally examined within the last five years and develop a programme of continued gearbox inspection. Note: The inspection of the hoist primary drives is especially important on MLT cranes. This is due to all the braking being done through the motor brakes. If the primary drive fails all hoist control and holding capacity is lost.
In these photos of an MLT crane we have inspected;
- The shaft for cracks.
- Ensuring the bolts are correctly torqued
- The gear profiles, bearing, bearing running face and the seal area
A typical winch drum motor configuration and the primary areas of inspection;
The inspection of cranes is completed according to recognized Specifications and Recommended practices of the American Petroleum Institute (Spec 2C and RP 2D), Classification Society rules and various state legislative requirements.
Inspections conducted during rig condition evaluation will ensure the crane certification is up to date, maintenance records are complete, the crane is visually examined and all the safety functions operate.
Inspections for crane condition evaluation will go further and may involve strip down inspections of brake components, examination of spline drives, hydraulic oil sampling, etc.
A full maintenance programme can also be put into place.
The function of safety devices is critical in avoiding accidents with cranes, as in the example here where the boom has been pulled over the top of the crane.
Initially caused by a technical fault in the controls but both the automatic safety functions and the manual emergency shut down failed to operate.
