CCTV SURVEYING is still important
How aware are you of the complexities of reporting on the pipework beneath your feet? It may represent a small proportion of on site costs but it needs to be accurate.
It may well be taken for granted in the 21st Century but closed circuit television inspection of underground pipework has come a long way since the first cameras entered the United Kingdom from America and Germany in the early 1960’s.
In those early days the cameras had permanently fixed camera and lighting cables which had the distances marked in foot intervals by cloakroom tickets fixed by clear tape. Care had to be taken to avoid the lens facing the sun to prevent burn marks on the tube and, of course, all pictures were monochrome. The in pipe distances were read from the surface with the manhole depth deducted. A line had to be floated through the sewer to enable cables to be attached for the camera to be winched forward for inspection (and then back out) and crew communication was by walkie talkie to stop and start the camera. Reports were handwritten but content was not dissimilar to today but photographs taken from the screen of salient points were the only visual record available.
Technological advances have resulted in more robust equipment and miniaturisation has given a greater ability to survey small diameter pipes. Modern lighting techniques together with the use of pan and tilt cameras means pipes and sewers up to 2000mm in height can be inspected by camera, relieving the necessity for man entry in most cases. Flameproof equipment, sonar and other specialist application cameras have been developed in response to client requirement.
Technology continues to offer potential benefits but asset managers need to work with contractors as partners to adapt equipment to industry specific needs. Recognition has long been given to the advantages of using the camera as a serious tool for both diagnostic and pre planning purposes. Survey information is now routinely used as the base for planning and costing renewal, renovation and maintenance programmes.
The Manual of Sewer Defect Classification, of which the fifth edition is shortly to be published, sets the parameters for reporting standards while the Model Contract Document for Sewer Condition Inspection (Second Edition) determines the specification requirements for reporting, equipment and pricing mechanism. As a result, computers are now routinely carried on inspection units to assist with speedy report production and an electronic video record. Preliminary information can be instantly relayed to the client when necessary.
The reporting parameters are constantly under review with changes in construction and renovation methods. The amendments to BS EN 13508:2: 2003 +A1 resulted in new codes for defects in plastic pipes and sewer linings and hence the update to the Manual of Sewer Defect Classification. Consideration is now being given to revising the Model Contract Documents in acknowledgement of the ongoing changes in technology.
Staff training has become essential for those companies carrying out drain and sewer surveys. To ensure consistency of stored data, the contract specification demands that team leaders hold a post course pass certificate for sewer defect classification. Develop Solutions run `OS’ courses in respect of main line sewer inspection, domestic and highway drainage. Training provision is another area under discussion with key players in the water industry.
Health and Safety requirements have also led to improvements in training and general hazard awareness over the years. The environment in which the equipment is placed is not becoming any less hostile, therefore safe working systems and adherence to health and safety procedures for the working environment both above and below ground for personnel as well as equipment is essential to the well being of the industry. Personnel working in sewers need to be trained in confined space entry, lighting, guarding and coning as defined by the New Roads and Streetworks Act, use of resuscitation units and any other training required by the employer or current legislation. Training requirements need to be regularly reviewed as much certification has to be renewed, legislation is revised and new equipment comes to market.
Water UK is a key player in maintaining a common standard and they are supported by the Highway Agency and the Insurance industry in acknowledging the need for training and consistency of reporting. The transfer of private drains and sewers has caused issues with knowing the pipework owner, not helped by the delay in transferring pipes laid since July 2011and the extension of contracts under the auspices of Tier One contractors has meant adjustment within the industry.
We now need the construction industry to recognise the level of training undertaken by a reputable contractor and how important this aspect of inspection can be to their industry. It is recognised that savings need to be made but this should not be at the expense of good training.
It must be remembered that the vast majority of contractors using cameras are deployed in carrying out blockage clearance work, utilising them to ascertain the reason for the blockage. Unfortunately many involved in this aspect of work have had no formal training in pipe defect classification. Beware - employing the cheapest may prove a false economy.
The industry is currently looking at developing an apprentice scheme for drainage operators which will cover site investigation, surveying, jetting and pipe laying etc. A look to the future for the good of the industry and we hope that all partners will be supportive of this initiative.
If you have any queries the National Sewerage Association (www.sewerage.org) will be pleased to assist.
NSA Secretary (www.sewerage.org)