Proposed Solution to Design Problem

Will McMorran met with Tim Lucas of Price & Myers on Friday to alert him to the design fault. A letter will be written to the client and signed by both parties. I would hope that I can post a full account of the design fault and solution if I can persuade McMorran & Gatehouse or Price & Myers to write a report on the issue as requested.

In the meantime the proposed solution is to remodel the design based on actual levels at site, rejig the right-hand end-plate and design and build a new left-hand end-plate. I was instructed to take new measurements and submit them to Will McMorran. I await the readings on site levels from the surveyors, Digital Survey Ltd.

On Thursday I went to see Stephen Mather who made the original end-plates to see if he would consider making another one. He was not at all amused and unfortunately Stephen doesn't want to make a new plate so it will have to be made down south somewhere.

At least everyone knows what the problem is and the solution.

Visit from the Engineer

Tim Lucas

Tim Lucas, from Price & Myers 3D Engineering, visited the site on Wednesday 26th September to review progress and get to grips with the distortion problem. I fear that it could be one of those projects which is designed on computer but in real life takes on a different form. Tim modelled the problem on his computer. His theory is that the bridge was designed to be built on a flat level surface, whereas in reality we have a difference in levels of some 560mm. There have always been a difference in foundation levels for this project. His immediate solution is to raise the lower end by 560mm and the problem will be greatly reduced. The other option voiced by me was to jack up the lower short end by 185mm and the higher short end by 65mm. Tim thought that this would best be done without sacrificial chocks. The beams will twist and my fear is that we are going to have a major headache defining and placing the balustrades.

It has been agreed that Tim will have a look at the geometry of the bridge and come up with some possible solutions. In the meantime I have asked Will McMorran of McMorran & Gatehouse to press for a meeting to review the problem and come up with a solution. Will McMorran remarked that there are many innovative design projects which throw up all sorts of problems which you never hear about...a solution will be found and you will hear about it!

Later the same evening Will telephoned me to say that he and his son had made a model of the deck. Will explained briefly that the design replicates a barrel vault and that Price & Myers took a line straight over rather than from one corner to the other. The consulting architect and the consulting engineers failed to pick up on this.

Construction of the Bridge

Stephen Mather securing End-plates to concrete foundations

On Tuesday 11th September, Stephen Mather secured the steel end-plates in position and with the help of Tim & Damian Fison and Charlie Poulsen we were able to swing the centre beam into position and secure it. The garden staff helped to move a workshop table and lathe to the site. A gazebo was erected as a temporary workshop and a generator was hired.


Charlie Poulsen & Tim Fison

At 08.00 on Wednesday 12th, the gardening staff, Neil, Nick, Kevin, Michael, Jimmyand Pavlov assisted Charlie and I to place four more beams in place. Charlie and I secured them and placed the necessary sacrificial chocks (spacers) and placed cargo straps to pull the bridge together. It was noticeable that the beams were going to tell the same story as found at Brackenside - namely that the bridge was not level throughout its length.

At 08,00 on Thursday 13th, the garden staff assisted Charlie and I to place the last two outer beams. They were secured and strapped into place. We started to construct a shelter over the site.




James Barber keeping his eye on the job
Contact was made with the consulting architect and engineer. Tim Lucas of Price & Myers is to visit the site on Wednesday 26th September. The left hand end has a distortion of 185mm whilst the right hand side has a distortion of 55mm.



On Friday 14th Charlie and I finished construction of a moveable cover over the bridge.

Trial Build at Brackenside

Marking out the profiles for the steel end-plates

I decided to undertake a trial build at Brackenside Farm, where I live. This would enable us to work through any difficulties with easy access to the workshop and a forklift. John Barber kindly allocated an area of concrete outside his grain drier, for the purpose. I contacted Peter Bennett of Digital Surveys to arrange a surveyor to set out the positioning of the steel end-plates, at the final site and at Brackenside. This was completed on Thursday 2nd August. There was a 5mm difference in slope between the two sites.

Stephen Mather and Stuart Graham of Holburn Smithy, anchored the endplates to the concrete on August 3rd.

Rolland and Hugo McMorran, sons of William McMorran the architect, pitched up on Sunday 5th August for a week of hard work assembling the bridge structure. This was completed on Friday 10th August. To our consternation we found that the two longest projections of the bridge upset the level of the deck. One end was out by 180mm and the other by 60mm. We overcame the problem by jacking up those corners, thanks to the analysis of the problem by James Barber who is studying engineering at Newcastle. The consulting architect and engineer both thought that the beams were fighting each other and that there was a need to have the noggins placed and tightened up within the structure to resolve the problem. The jury is out on this until the visit of the engineer to the finall site on Wednesday 26th September.



Rather than begin to take measurements for the oak noggins which are to seperate the beams, Charlie Poulsen and I decided to take the bridge apart and get it down to the final site.

The beams were delivered to the site by Hugh Burn on Wednesday 29th August. Thanks to the Estate forestry deppartment and Neil Mole we were able to bring the beams through the wood and into the garden more easily than had been originally antiscipated.


Hugh Burn at the controls!

Arrival of Timber at Brackenside & Bending of Beams

Somerscales delivered the 7 beams and timber for the decking and cladding on Monday 16th July, 2007. George Barber and I immediately laid out the beams on trestles and attached tractor weights to the ends of the beams in order to create the required curve in the timbers. The beams then sat for three weeks bending gently.