With a growing number of reported incidents to the BDA regarding the damage and failure of cable percussion drilling rigs, compressors and trailers whilst towing on the public highway the following information has been produced in an effort to eliminate these occurrences.
The most common cause appears to be inadequate planning. Items of plant have been pulled or winched into position over rough, uneven terrain. These trailers are fitted with road going wheels, axles, brakes and are not designed for some of the rugged ground conditions that they are being exposed to.
The brakes, drums and bearings are becoming clogged with detritus, and often with no facility to wash down and inspect the extent of any damage, trailers are then being towed on the carriageway where; the detritus can foul the carriageway, damage the bearings and/or brakes, which causes overheating. This leads to ineffective braking, potential total failure of the braking system and catastrophic failure of the wheel whereby the wheel and brake hub become detached.
This is a significant safety concern and should be of the upmost importance to the driver, who, potentially could face prosecution. There is a direct interface with third parties using the carriageway which could present a potential fatal consequence. This will result in a prosecution from the Police in terms of the Road Traffic Act 1988 and a prosecution from the HSE in terms of the Management of Health and safety at Work Act 1974 - both may result in an unlimited fine and or imprisonment, not to mention the moral implications.
To eliminate this circumstance we must ensure that a safety inspection is carried out on all towed plant prior to entering on to the carriageway. Any detritus is removed, the braking system is checked, all lighting and high conspicuity marking is clear for other road users and the item is in full working order and documented. If any of the running equipment is found to be defective then it must be corrected before being used on the carriageway.
Where soft boggy or steep sloping ground is expected or encountered, provision for the use of specialist ancillary plant, with a competent operator, should be sourced or track matting/bog mats used to eliminate the risk of damaging the plant.
Cable percussion rigs must not be winched into position using the main winch. This practice is in direct contravention of PUWER 1998.
Author: Jon Christie, Chair of Safety Committee, British Drilling Association