Justification for using Manbasket on Land Rigs and Hoists
The purpose of the article is to clarify the safety related points of Manbasket usage onland Rigs and Hoists.
Crane vs Mobile Elevated Working Platform (MEWP)
MEWP practically cannot be used for land Rig/Hoist operations for few reasons:
- It cannot reach areas on the MAST/DERRICK as it is designed only for vertical movements to reach areas only within the boundary of its base. If used ‘Overreaching’ Unsafe Act can come up.
- MEWP Cannot reach height of the Mast/Derrick higher levels
- It is not financially feasible to keep Crane/Forklift and MEWP on the Units, as Crane/Forklift cannot removed from service completely, i.e. need a mean for lifting loads
Crane Safety systems
Crane is designed for lifting, and in case of Manbasket it is used as per design for lifting.
Cranes are equipped with many Safety systems that include but not limited to:
- Weight Indicator
- Drum cable layer limit
- Boom hoist limit
- Block hoist limit
- ACS (Automatic Crane System with voice alarm),
- Slewing automatic stop system,
- Outrigger status detector,
- Boom derricking / telescoping holding valve,
- Overhoist prevention device,
- Drum lock device (on aux. winch),
- Winch holding valve,
- Automatic winch brake,
- Winch drum roller,
- Hydraulic safety valves,
- Outrigger lock pins,
- Slewing lock,
- Joystick control safety stop system,
- Hydraulic oil temperature warning device,
- Hydraulic oil return filter warning device
- Slew limits (offshore) – is restriction to slew the crane boom to avoid collapsing with derrick, which is available with very expensive onboard computer equipped latest cranes. – NA to land cranes
- Heave compensator for cable (offshore) – is spooling block in and out based on the load weight which can change due vessel movement on the waves, which is available with very expensive onboard computer equipped latest cranes. – NA to land cranes
- Manriding mode (Offshore) – is a slow movement of the crane, which is available with very expensive onboard computer equipped latest cranes.
Successful Precedence of Manbasket in the industry – Justification for use
Manbasket are widely used (daily 2 times a day, 5 lifts each, 4 people each) in Offshore to transfer personnel to/from the crew change vessels.
As well as daily use for all work at height activities including daily Preventive Maintenance, painting etc.
Additional to our use, there is an additional sling attached from basket immediately to headache ball of the whip line.
Manbasket proved to be much safer than manriding activity conducted by using Manriding winch.
- On Land rigs where Mast can be accessed from outside of the Mast perimeter, Manbasket is safest method of access.
- On offshore rigs where the Derricks are enclosed, Manriding winch as well as In-Derrick Cherry Picker are used.
