The Merafield Bridge was built in 1969 as part of the Plympton bypass and is now suffering from Alkali Silica Reaction, more commonly known as 'concrete cancer'. It will be replaced with a new structure but first the existing bridge had to be demolished; this was planned for the weekend of 14th / 15th May. JET Plant Hire played a key role in this £6.4m project and was still working on the bridge just over an hour before it was blown up.
A 2m planer did the majority of the pavement removal work on 3rd May, removing 800 tonnes from the bridge deck at a depth of approximately 200mm.
The following day a 1m planer continued the demolition preparation and cut the kerb lines. Then on 14th May the 1m planer returned to cut the tie-ins and to profile the road to the proposed new levels. This was the night of the ‘big bang’.
The 1m planer crew were on site during the demolition of the bridge deck and suspended work 90 minutes prior to the charges being detonated, which had been laid a few days before the explosion. An hour before the detonation, a 150m exclusion zone was enforced and checked by Gilpin (the Newton Abbot-based demolition contractor).
JET Plant’s team couldn’t see the bridge as it came down, but described the noise as sounding ‘like a very loud firework display’ as the charges detonated in sequence – charges at the top of the bridge fractured the structure first, followed by explosions at the base, which brought down the bridge. The carriageway was protected by a cushion of wood, earth and stone and was closed for only 15 hours.
The resulting rubble (2,500 tonnes of concrete and 400 tonnes of steel) was immediately ‘attacked’ by an army of machines to break down the larger items ready for removal. Fifteen minutes later JET Plant’s 1m planer was back at work, finishing off the tie-in work.
The 47 year old bridge is now gone and will soon be replaced by a new bridge, to be built adjacent to the original site. The new bridge is expected to open towards the end of Summer 2016.
At the end of March, JET Plant Hire undertook the planing work on two roundabouts - Peel Common Roundabout at Fareham and St Margaret’s Roundabout at Titchfield on behalf of surfacing contractors L Kattenhorn & Partners Ltd.
The jobs were running on the same night so David Kattenhorn supervised the Peel Common project whilst his brother Lee supervised work at St Margaret’s. The two sites were 6 miles apart.
The job at Peel Common for Dyer & Butler involved removing 3,600 m² @ 45 mm depth, 720 m² @ 100 mm depth and 400 m² @ 320 mm depth. The work was restricted as the road had to be re-opened at 6 am, but it quickly became apparent that significantly more planing would be required at the site over the remaining shifts. Fortunately, JET was able to add another planer to the job at very short notice.
The job at St Margaret’s for Mildren was similarly underestimated with more planing required than originally thought; involving the removal of 5,100 m² @ 45 mm depth and 2,500 m² @ 100 mm depth. JET Plant were able to react swiftly to the change in requirements and a 1m planer was swapped for a 2m planer for one night, which ploughed through the work.
David and Lee Kattenhorn were impressed with JET Plant’s performance, from the initial planer specification for each job through to completion and sweeping. JET Plant’s crews managed well in the face of changing requirements and delivered solutions for the problems thrown up by those changes.
As part of Wiltshire County Council’s ongoing maintenance work, specialist road planing contractor JET Plant Hire Ltd were asked to tackle a site with very limited access. The only way in and out of the site was through a tunnel under a railway line with a height restriction of 11’ 3” and a 90 degree bend at one end. A housing estate lay on the other side of the tunnel.
Working closely with its customer, JET Plant Hire developed a plan to overcome the restrictions and undertake the work with the minimum of disruption to local residents and motorists.
Manoeuvrable, four wheel tippers were used which could pass under the low bridge and around the tight bend and bring the planings out to a designated tipping area close by. A 13t excavator re-loaded the planings onto eight wheel tippers which were taken away for recycling and re-use. This process was then undertaken in reverse to bring the new asphalt in, under the bridge, for the resurfacing.
A local resident and retired highways engineer commented,
“I have to admit that I spent considerable time at the roadside taking pictures, with individual’s permission where appropriate, and saw the team at work on many occasions. To the last man, the team were always polite, considerate, and incredibly tolerant of both myself, and the seemingly never ending procession of motorists. They always seemed to be proud of what they were doing, and happy to explain the process and machinery being used, when time permitted. I have never seen such a smooth running operation – everyone and everything appeared to be in the right place at the right time.”
The smooth running of the site was a testament to the advance planning and close liaison between JET Plant Hire and their customer. What potentially could have been a very difficult site, creating lots of local disruption, in fact ended up finishing a day early much to everyone’s delight.
The 40 year old bridge located near Newton Abbott in Devon, which carries the A380 dual carriageway over the River Teign Estuary, was in need of urgent repairs to a failed expansion joint at the north end of the viaduct. The work involved removing the road surface and installing a new waterproofing layer before the road was resurfaced.
Early involvement from JET was requested by the contractor. JET was required to give input on the H&S aspects of working on a viaduct and milling requirements to remove the existing surfaces down to the waterproofing layer. The underlying waterproofing was classified as a hazardous waste. Removal of the carriageway surface above required milling to a fine tolerance to minimise disposal costs of the waterproofing material.
A tracked 1m planer was used and the performance of the team delivered to meet the customer’s high expectations and standards.
In April JET Plant secured a contract in Devizes to remove the top 40mm of material in a particularly challenging, residential location. Laid by the original developers, the surface on this prestigious site had failed and been repaired, but the resulting appearance was poor so the decision was taken to resurface the whole area.
This residential site was particularly difficult in that there were no footpaths in front of the properties; the area to be planed out ran right up to the walls and front doors of the houses. To further complicate matters there was only one main access road with two adjoing cul-de-sacs.
After visiting the site, a plan was agreed with the customer and council representatives to use a 350mm and a 500mm planer. Each would have a four-wheel skip tipper with it to enable the planings to be taken away and recycled locally.
The work was scheduled for completion over three days but, despite the level of difficulty, by working methodically and professionally to the plan, JET were able to finish a day ahead of programme with both the customer and residents satisfied.
JET Plant’s customer commented “This was a particularly high profile and difficult site, but being able to work closely with JET from the very start of the planning process, meant we were able to deliver a high quality job and substantial cost savings. A job well done!”
JET was contracted to plane out 270,000 m² of asphalt on the M48 from the Severn Crossing to the M4 in just under 8 weeks. JET’s high-performance 2.1m cold planing machine made light work of this mighty task — the largest contract undertaken by the company to date — enabling an average output of 30,000 m² to be achieved per day.
Most of the work on this high pressure site was undertaken at night and in extremely tight working conditions. There was a particular emphasis on health and safety; the requirements included a three man crew, equipped with an intercom system to ensure good communications around the machine, and a banksman, all in appropriate PPE.
With a standard milling width of 2.10 m and high engine power, the machine is fully equipped for large-scale sites, delivering high output with maximum flexibility. The planing depth of up to 320 mm enabled the entire pavement construction, from the wearing course down to the base course, to be removed in one single pass, saving time and ensuring high productivity.
Managing Director, Sean Witheford commented, “The 2.1m machine was ideal for this contract and with careful planning our very experienced operators were able to meet the output targets, completing the job on time, whilst also complying with the site’s rigorous working conditions.”