Cambridgeshire-based drainage contractor Dal-Rod Cambridgeshire recently undertook its first ever lining operation with the BRAWOLINER® system on a project in Epping Forrest. Working for managing contractor AMEC, the project was required to renovate drains at the Epping Forest college campus. The local authority required rehabilitation of the sewer, which runs under a main highway between the college and a public walk way, to be completed using Brawoliner® as a preferred method of repair. The majority of the pipes comprised 225 mm or 150 mm diameter pipes which were suffering from numerous cracks, joint displacements and fibrous root intrusions, as well as egress & ingress of sewer and ground water flows.
Ground conditions on the project were very wet and muddy due to recent consistent rainfall which caused numerous problems with the set up of the equipment and resin impregnation of liners prior to installation. In total two liners needed to be installed. It was decided that the first should be installed using an air inversion hot water cure technique and the second using a heated water inversion technique with the water being subsequently heated with a hot box. Dal–Rod also had to undertake other lining works at the site but these were completed using standard polyester liners and patches. As well as the Brawoliner® equipment Dal-Rod also utilised a tractor unit, CCTV tractor unit with a high flow tanker/jetter.
Ground investigations were undertaken prior to the lining works using CCTV and drain location techniques to ascertain the exact position of pipe work needing repair, its condition and to ascertain any lateral connections within the system that would require re-opening subsequent to the main lining work.
PROBLEMS AND TIMING RESTRICTIONS
The location of the works meant that project timings were strictly limited with the lining works having to be completed within 24 hours of the start of working with operations continuing through the night to ensure completion. In the event, the project was completed within 18 hours of start-up which included all finishing works and tidying of the site. The project started on the 20th August, 2007 and finished in the early hours of the 21st.
As well as timing restrictions, Dal-Rod also encountered a major problem with high water flows from site which required over pumping and lifting out with a vacuum unit. There was also constant use of the lateral connections on main lines, which had to be isolated and re-cleaned. With the timing restrictions and the need to operate at night there was also the difficulty of noise pollution when inflating the liner in the early hours of August 21st.
These working restrictions also meant that there was a need for special arrangements to be made to ensure silent generator operation on site and the use of other low noise equipment for cleaning and repair works which had to be carried out during unsociable hours.
All in all the client and its managing contractor were very pleased with the results of the work, the speed with which it was turned around and that it was completed on target, ahead of schedule and on budget.
Commenting on the project Mike Pollard, managing director of Dal-Rod said: “This was our first ever Brawoliner® installation, which we took on after attending a course in Germany with CJ Kelly Associates Ltd and undertaking all the relevant training for all of our operators. We subsequently purchased all of the relevant machinery. Carrying out a 225 mm diameter lining on an unknown material with unfamiliar equipment is, at the best of times, a difficult job, however the project went smoothly and, on inspection, the finished product was absolutely 100% wrinkle free.”
On completion of the lining work and CCTV surveying the liners in situ, DVD’s were supplied to client as proof of the success of the Brawoliner® installation and the quality of the repair. Brawoliner® installations come with a 25 year guarantee as recommended by CJ Kelly Associates Ltd.
Mike Pollard continued: “We are now hoping to follow up this first installation with the larger diameter Brawoliner® with further projects in East Anglia and further afield as required. We are happy to work on a sub-contractor basis if required. The acquisition of the Brawoliner® technology also compliments all of the techniques that we already have in our portfolio and strengthens our position in the market place in our area, making us one of the leading drain repair companies in East Anglia.”
For C J Kelly Associates Ltd, John Kelly, managing director said “We were extremely pleased to be able to bring the Brawoliner® technology to Dal-Rod and have been impressed by the way in which they have taken to the product. We will continue to support their efforts to utilise the system throughout their area of operations and are on call at any time with advice and experience should they need it.”
The Brawoliner® system uses a seamless lining textile fabric that is applicable to pipes from 75 to 255 mm diameter, with wrinkle free installation around 90o bends. The system is generally compressed air inverted from an inversion drum and can be used as an ambient or hot water cured installation. The system can also utilise a water inversion scaffold tower should circumstances be appropriate.
The Brawoliner® system is designed to answer some of the more pressing environmental problems with more established lining system resins across Europe, and does this by using environmentally friendly resins and the system is manufactured to ISO9002 standard.
Brawoliner® has also been presented with an award for innovation in the Rhineland-Palatinate region of Germany on the basis that it was specially designed to meet the latest environmental standards.