Colchester Engineering Society
Colchester Engineering Society

Recent Lectures


Autumn / Winter Programme 2016-2017

Friday 17th March 2017: Ipswich Flood Barrier Presented by Neil Dorland, Site Project Manager for VBA.


The client for this major project is the Environment Agency who has been engaged in a major flood defence scheme for Ipswich for about 10 years, with an overall cost of some £58M. This particular part of the project, a flood barrier (not unlike the Thames Barrier but smaller) is worth £21M and is being undertaken by a consortium of three companies VolkerStevin, a civil engineering contractor specialising in land remediation and regeneration, water and marine infrastructure, and flood and coastal protection. Boskalis Westminister, one of the most experienced dredging and marine contracting companies in the UK. Last but not least there is Atkins, an internationally respected design, engineering and project management consultancy. The EA potentionally uses five main contractors for its major works who nevertheless still have to tender for the projects but their capabilities are known.

A local Ipswich company, Jacksons has already built some of the new harbour walls as this was Phase 1. Phase 2 concerned excavating a large "elderly and somewhat fragile 132 kV electric cable that ran across the river bed just at the point of where the flood barrier was to be located. To overcome this obstacle two shafts either side of the lock had to be dug and a connecting tunnel constructed to house the cable.

Phase 3 was the development of the tidal barrier, the control room and the wet dock flood walls and it is this phase currently under construction. The steel gate will be located to position during the coming months. Due to no manufacturing or skills capability in the UK this part of the barrier is being made in Holland.

To house the gate a 30m² coffer dam has been built with a radius base in which the lifting gate will spend most of its time. There are 48 piles of 1016mm a depth of 37 to 58 mts. passing through a geological fissure and soft chalk strata. This whole structure where the barrier will locate has consumed 750 tonnes of steel reinforcement and 7.5k cu mts. of concrete. The barrier gate weighs 190 tonnes, is 22mts wide, 9 mts in the vertical, has a design life of 100 years with specified regular maintenance regimes and has access for internal inspection. A mock up has been built on the quay side to demonstrate this capability to the customer. There are several different positions to which the gate can be manoeuvred. For example to allow for flushing river detritus from the flat position or to allow the gate to be lifted into the air, looking like a giant mushroom, for inspection purposes. The gate has a drive mechanism of 2 drive cylinders that have a 16mt stroke.

Innovation and value engineering have played an important part in securing the contract. Normally with such a structure, when the barrier is lifted for maintenance a mobile crane has to be brought to site. Crane hire for the entire duration of maintenance work is very expensive. The incorporation of additional lifting pins to allow the barrier to be lifted to the mushroom position, without a crane, is designed to minimise maintenance costs. The barrier seals (which have a 25 year life expectancy) that would normally be located on the side faces have been positioned on the inner face on either side a little inboard and away from the edges to also reduce maintenance effort. This project is unique to this location and includes several innovative features as described above. For civil engineering structural work of this type within the barrier area there is only a maximum tolerance of 5mm allowed. For a civil engineering job using masses of reinforced concrete which must be of a particular mix and consistency this requirement is, just let's say daunting and very rarely heard of if at all. Nevertheless the technical teams are very confident. Because the concrete specification is so crucial VBA have established their own testing and quality laboratory on site to get "instant" results.

This project has demanded a considerable amount of specialised dredging and the reclamation of material from a new channel and from the gate position. The mud etc. approximately 5k cu. mts has been stored in special geotextile tubes similar to huge sausages, dewatered and cleaned. The resulting silt plus a special additive will be processed by Hydrock, a specialist contractor and used as back fill to build up the bank which will then be landscaped.

The Control Room building will sit on 24 piles and a reinforced sub structure. It will be finished with slate and stainless steel cladding which should look futuristic in its own right. The stakeholders in the project are Associated British Ports, DB Shenker train operator (goods) Persimmon Homes (accommodating much of the site work), Net Work Rail and the Environment Agency as the client.

This project is not all hard engineering. Neil referred to modern computer control techniques used to manage the project, mentioning the need for lucid, fluid, up-to-date communications, data and information in real time, which is a boon to productivity and cost control. It is to this end VBA together with the EA have developed a system called Building Information Modelling with 3D model links which allows total information exchange in real time between any of the operating offices regardless of where they are located. This detail is stored and can be retrieved at will and / or modified as appropriate. Any thing from photographs, drawings, text, spreadsheets, material specifications, costings, H & S issues etc.

The evening was well presented, packed with detail and bang up to date. Two hours well spent.


Bob Barnett.



Friday 17th February 2017: From Dream to Steam by Rob Morland BSc (Hons) CEng FIET, Director Electricals, A1 Steam Locomotive Trust and P2 Steam Locomotive Company.


Rob introduced himself and how he became involved in the Trust and soon discovered that the driving force behind the whole enterprise was and still is Mark Allat. As a lead into the evening Rob proceeded in telling how the Trust started which was really due to a number of like minded soles who were aggrieved that no steam engines from the LNER railway days existed but there are plenty from the railways that served the western, midland, eastern and southern regions. The reason for this is that following the rapid advance of dieselisation in the 1960’s there were no units of the A1 variety that had been sent to the scrap yard in Barry in Wales as with so many other engine types. The maximum time in operation for the A1s was only 15 years, no time at all.

Photographer Rob Morland of the A1 Trust


It was felt that this situation should be rectified and so in 1990 a group of people came together to share an extraordinary ambition - to construct a brand new Peppercorn A1 Pacific steam locomotive. At the time critics said it could never be done. However, an amazing tale of cooperation, skill and sheer hard graft has proved the critics wrong. This group formed The A1 Steam Locomotive Trust and after nineteen years of incredible effort that locomotive, No. 60163 Tornado, moved under its own power for the first time in 2008.

Huge amounts of endeavour were called upon over these years even before metal was formed or cut. What drawing existed in many instances had to be interpreted as to what was actually meant as specific details and / or tolerances were inconclusive or not recorded, just margin notes that meant something to the experienced man of that time. Measurements had to be converted into metric units as sheet and bar steel is now manufactured and sold in metric units. Many of the suppliers that have been used had to be sourced for their specific capabilities. Unfortunately the company contracted for the boiler work now no longer exists and the Trust now has to go to Germany for similar work and specific maintenance. Unfortunately the UK foundry that was used for the Tornado does not exist for the latest project. In many instances fastening and fixings were individually made. In order to run on to-days railway many more safety systems had to be designed and installed. But not only that a sufficient supply of water has to be carried and thought about as there are no water stops on to-days railway. Now the same group is building a second new locomotive - this time it is a Gresley P2 2-8-2 to be named "Prince of Wales". When it is complete it will be the most powerful steam locomotive operating on the British main line.

The A1s were designed by Arthur H Peppercorn (29 January 1889 – 3 March 1951), the last Chief Mechanical Engineer of the London & North Eastern Railway (LNER). They were the last in a line of famous express passenger steam locomotives for the East Coast Main Line that included the Stirling Singles, the Ivatt Atlantics and the Gresley Pacifics.

The original 49 Peppercorn Class A1s were ordered by the LNER and built at Doncaster and Darlington for British Railways (BR) in 1948/9, after the nationalisation of the railways. As designed they were ideally suited for the post-war world of poor maintenance and heavy trains, with their 50sq ft grate allowing them to use lower grade coal than their predecessors. The final five were even equipped with roller bearings enabling them to go for an average of 118,000 miles between heavy repairs, making the A1s the cheapest to run of all British steam locomotives in the same category. They were also the most reliable of all of the express passenger steam locomotives owned by British Railways.

The A1 Trust has over 2500 regular supporters (Covenantors) who have all played some part, small or large, in guaranteeing that we have steam on the main line in the 21st Century. The P2 project is in the very early stages of build but has had a very good start to its life, with over £2 million already pledged in just two years towards the expected construction cost of £5 million and metal has started to be cut and parts made.

There many engineering challenges of maintaining a steam locomotive to meet the tough requirements of today's main line but with the experience built up with the Tornado and knowing that there are still suppliers of the highest quality and abilities not just in this country but also in Europe the future looks bright. The presentation was excellent with very many images and we were assured by Rob that there were very many more and he could have spoken for much longer. The whole evening was well appreciated by the audience judging by the many positives comments heard by the author.

Bob Barnett


Algorithms, Will they Rule Our Lives? - Professor Abdel Salhi - Department of Mathematical Sciences University of Essex. Friday 7th October 2016


The word Algorithm is not another word developed by the computing industry or Silicon Valley but derives from a gentleman named Muhammad ibn-Musa al-Khwarizmi who was a Mathematician and lived in the 9th century in south central Asia and later in Baghdad. Development of the use of Arabic numerals (what we use to-day) and how they can be used was actually developed in ancient India. So we have Arabic mathematicians working with Hindus and Muslims laying the foundations for what are used in the western world to-day.

In one form or another algorithms have been around for as long as man has although not recognised as such. Each one of us on a daily basis makes decisions and before reaching a conclusion consciously or subconsciously analyses the data / information either based on factual knowledge or best guess to hopefully make the correct decision. We are in fact processing an internalised algorithm, of course not in any way as complex as those used to solve problems for which computers are most suited. Algorithms can be pictorial e.g. flowcharts, graphical e.g. bar charts, tabulated and mathematical. All with the aim of solving with a high degree of outcome satisfaction a complex problem.

There are many different types of algorithms depending upon the type of problem to solve and new ones are always being developed. As the world in which we live gets more complicated and demanding with more technically advanced devices whether it be from a washing machine to cars or mobile phones they rely upon algorithms. The use of algorithms, not recognised by the bulk of the population are in e.g.-

  • The many and varied programmes found in the domestic washing machine.
  • Fly by wire aircraft and you thought the pilot was flying you to your holiday destination!
  • Decide what advertising should be customer focused.
  • Monitor safety and security in nuclear power stations.
  • Decide strategy and tactics in warfare.
  • Recognise us through our faces, style of writing, gate, and fingerprints.
  • Analyse sentiments to advise which products to push merchandise in our direction.
  • Advise on investment decisions.

The list just goes on.

It may be thought, looking at the above list that there may be very few algorithms but that is wrong because every field of science, engineering, medicine, finance etc. have their own complex problems and therefore have different needs for inputs, data and desired outcomes. Hence different types of algorithms exist. Some can be defined as Merge and Sort, Quick Sort, Cryptography used for security in on-line transaction work, Page and Rank on which Google search and their fortune is based, OK Cupid Date Matching, Simplex algorithms in management operations when linearity is the norm, Optimisation and many more.

Professor Salhi may have also surprised his audience by giving examples of how nature is playing its part in inspiring the mathematicians and scientists in the this field by giving examples of Swarm Intelligence and basing algorithms on this by studying ant colonies. The derived algorithm simulates the behaviour of foraging ants in determining the shortest route / path from and to their colony and source(s) of food. Then there is the Plant Propagation Algorithm in this case the Strawberry Plant which gave inspiration from nature in the way plants propagate to further their species and survive, (developed at Essex University). Although it may seem a totally random process with no end game but just chance that would be a wrong assumption and by studying the natural environment and applying mathematics new algorithms can be developed to solve ever increasing complex problems of optimisation, doing the least to maximise gain. In our example to aim being able to find the best plot that will give the best growth by sending out "runners."

A more real life Optimisation problem based on the above as solved by Prof. Salhi and team was that of labour scheduling at the Port of Felixstowe and handling containers. Prior to the solution the required number of suitably qualified operatives in a number of skills to handle the loading / unloading using the RTGs (Rubber Tyred Gantry) - these vehicles are the ones used for moving and stacking or unstacking the containers on the dock side) was achieved by experience and best guestimate. This meant to much expensive labour could be hanging around or too few would be unavailable and the job taking longer. Whilst the project resolution does not give a 100% solution with the algorithm available it is an improvement and cost effective achievement than reliance on the purely manual effort.

In summary: -
Algorithms become more and more important in our lives.
Important decisions to be taken by smarter and smarter algorithms.
As real world problems become more complex we turn to Nature for inspiration to design these algorithms


Bob Barnett.



Recent Visits

Visit to A & B Glass Company Ltd. – Tuesday 8th August 2017

Although it is August the day was grey and overcast and later very, very wet.  However, the first of two groups of CES members and guests, (the second group on a dryer Thursday 10th) were treated to a warm welcome as was the second group by Dave Johnson who is responsible for Site and Product Quality and Environmental Certification matters.  All certifications are to recognised international standards, the company being regularly audited for compliance.  Over tea and biscuits and introducing us to the company using film and discussion and acting as one of one of our guides was Dave Richardson, the site Production Manager.  Our second guide was Andy Tatum the site Supervisor who had been with the company for 31 years.


Following the initial introduction we progressed to the factory for our factory tour.  I for one and I think I can write on behalf of our group had no idea as to the size of the site, operation or business.  A & B Glass has been in business for a little over 30 years but only based in Sudbury since 2002 having bought out a local company.  The current location is their third due to continued success, business growth and expansion.  Via takeovers and mergers other companies have been bought and there is a further manufacturing plant in Huddersfield with a distribution centre in Gloucester.


A & B Glass manufacture their own entire product range e.g. windows, doors (front, bi-fold, patio etc.) and conservatories.  The glass and plastic profiles (frames) are of UK origin produced in other parts of the country but the metal work e.g. locks and stays are imported from China as there is no suitable UK manufacturer.  They have their own installation teams, sales teams and operate all their own transport, delivering daily countrywide.  Interestingly they also manufacture for other installers of double glazed products.  For the group about 3.6K windows and doors are produced per week.


Needless to say much computing power is utilised in the business and manufacturing processes, keeping track of a multitude of different orders, monitoring and controlling the automated parts of the process and stock control etc. etc.  There still remains a considerable manual input working across two shifts and possibly soon embarking on a four shift system.  Within the manufacturing process all glass is cut to order size on site from large sheets e.g. 3210mm by 2250mm by 6mm.  In order to maximise the sheet usage and minimise waste the cutting machines are automated and calculate the cutting configuration from each sheet for the orders that have been input to the programme.  Toughened glass is bought in already cut to size because the toughening process has to be performed after the glass is cut and this demands a special process, one for which A & B is not set up for and would be an uneconomic proposition.  Unfortunately the cutting M/C tables are Italian as there is no UK made equivalent.  Once the glass has been cut to size per order they are matched, assembled with the spacers, sealed and then placed in a closed process special but expensive M/C and Argon gas is injected into the sealed unit.  Each panel is then ready for being assembled into the relevant cut to sized profiles the ends of which have been shaped and mitred on automated equipment.  All scrap glass and profile material is recycled as can your own old units.
A more recent innovation has been to set up a small operation where a range of coloured glass can be cut, arranged into patterns / shapes and leaded (manually) into windows and doors as may be required by the customer.  This operation used to be a bought in item but is now done in house.


If a customer wants a colour other than white, a spray paint shop facility is available but also profiles can be covered in what is known as “foil” which comes in a range of colours and is part of the profile manufacturing process so has to be bought in.

There are three divisions to A & B Glass, the Commercial (retail) serving the domestic market and refurbishment segment and commercial industrial projects, New Builds, serving the construction of new estates and Trade, supplying products to other installers.  All this with a total group labour force of 356.


Quality, customer service and care for the environment are key drivers of the business and these are proven factors demonstrated by the continued growth in the business.  Both groups enjoyed the afternoon visits and the time was well spent.  Once again it was a treat to witness a successful manufacturing company.


Bob Barnett


Visit to Percival Engineering - Ardleigh – Tuesday 11th July 2017

On this dismal wet summer evening the light shone through for the attending 26 members and guests with a visit to this local family run niche market engineering company in the Ardleigh countryside started by and run by Richard or as he prefers to be known as Percy.  He started the business as most entrepreneurs do in a small way following redundancy doing basic type repairs and jobbing engineering work but slowly was asked to do more demanding and specialist type of work as his reputation grew.  The majority of work is now gained by recommendation, word of mouth and repeat orders.  You might think that Percy had a strong engineering family background but his deceased father was in fact in market gardening and there are some large green houses to support this still on Percy’s large plot of land.


These days and for quite sometime now Percival Engineering has been heavily involved with and has built a nation wide reputation which has also extended to other countries for specialist gear cutting and steam engine transmission systems.  The work often means that the projects require full strip downs and rebuilds which presents considerable challenges when frequently working with something 100 or more years old with no plans, drawings or technical details of any sort and having to define your own datum points.  What you have is what stands before you.  This is where Reverse Engineering with the skills, competence, experience, and knowledge of Percy and his craftsmen come into their own.  The individuals ability to be able to problem solve and “think on their feet” is an absolute must as is their ability to be multi talented and able to operate all of the machines at their disposal on site.  Most of the machine tools are of the ‘60’s and ‘70’s and are ideal for the type of work undertaken, mass production not being a requirement although there is a CNC machining centre but this is seldom used.


The aim Percy and his team have for each project is to do all the required work to the highest standard possible but in such a way that on the finished job no work appears to have been carried out and everything still looks original.  Percival Engineering is a ‘go to’ organisation for many companies from any where in the world when specialist small numbers or one off out of the ordinary component parts is required because no matter the part it is known that it will be made to a high standard.


Although it may not seem much but to give a small example of the skills needed Percy said that he would expect in general to make a key and keyway to fit so that the key could be removed in100 years time as easily as one is removed from something now 100 hundred years old would take about eight hours considering the ‘bluing and scraping required to get a perfect fit.  


It is a sad fact that the machines used in the workshop come from  British companies that over the years have gone out of business for various reasons e.g. lack of the type of work they were perhaps expert in, their work can be purchased more cheaply from overseas or Europe or the bank foreclosed the operation etc.  However, for Percy it has been good news because he has been able through the auctions to pick up good machine tools at a good price.  All the really big machines have been snapped up and moved to India so they in many cases are working on 50, 60, year old M/C tools.  As might be guessed the work undertaken demands particular specialist grades of steels and this comes from America or Italy via a stockist in this country, there not being a maker of these steels in the UK.


A most enjoyable evening to see solid British engineering craftsmen skills still in demand and not just from the UK but also far afield and to think it is happening tucked away in the parish of Ardleigh.  Who would realise that in England there are about 5 thousand steam engines and in Ardleigh there are 14.  Another company out of the many Colchester can be proud of.


Bob Barnett



Visit to Ransomes Jacobsen Ltd. Tuesday 20th June 2017

A party of 17 members and guests braved the hot sun and blue skies and travelled to Ipswich to visit Ransomes Jacobsen for what turned out to be interesting and informative afternoon.  Ransomes was started by Thomas Ransomes in Norwich just over 250 years ago but moved to Ipswich where it has been based for nearly all of that time.


Many of our more senior Society members will know Ransomes for designing and making agricultural machinery ploughs in particular but that side of the business went a number or years ago.  For many years Ransomes have been a renowned world leading company in the design, and manufacture of grass care and maintenance machinery and equipment.  You would not believe the development work and technology that goes into such machinery which is as a result of customer demand.  Customers being grass cutting and maintenance contractors, golf clubs, and local authorities etc.  This demand coming in the form of cutting effectiveness and efficiency, operational cost and performance.  This feeds back into how manufacturing out put is achieved and this was demonstrated by being walked through the manufacturing process by their very enthusiastic Quality Team Leader, Mick.  What was out of bounds was the development and testing facility, quite understandable.  Where a process can be automated it has been e.g. bar and pipe bending where by just one operator and one machine now does what used to be done by several and take much longer and having to hold more work in progress, all added cost.  There are also CNC turning machine tools, surface grinders, robot welders and laser and plasma profile cutters etc.


The new technologies (not so new these days) has meant that more can be produced with less there is less work held in progress and product quality is more consistent.  All of this means a more competitive edge.  In days gone by over 3000 people were employed but now it is about 10% of that number.  Of course in those days Ransomes had their own foundry and all that went with that type of set up but that no longer exists.  Needless to say there is much that is bought in mainly from specialist suppliers e.g. hydraulic motors, petrol engines, wheels etc.


Quality, Heath and Safety and the Environment are all considered to be important for in house purposes but are also good for marketing and selling so Ransome are certificated to internationally recognised standards.  Training is also considered to be an important function by both apprenticeships and customer product training.  It was interesting to note that apprentices do part of their training at Colchester Institute.


Not only do Ransomes produce new machines, they also buy back machines, completely overhaul and refurbish them and sell them on which has proved a successful undertaking. All in all a very interesting afternoon proving that engineering and manufacturing for world wide markets is still alive and well in East Anglia.


Bob Barnett


Visit to Flakt Woods Wednesday 13th July 2016


Manufacturing in Colchester is alive and well as was demonstrated in the latest summer visit this time to Fläkt Woods. Twenty three members and guests, unfortunately one going sick at the last minute gathered at the company's reception and were then shown to a conference room for tea/coffee and biscuits and introduced to our host Peter Hunnaball and then the presenter for the first part of the visit's proceedings.

Fläkt Woods or possibly better known to most Colcestrians as Woods of Colchester, a Queens Award for Industry award winning company is one of a few remaining long established manufacturing companies in this part of Essex with an international reputation for its product design and manufacture. For many years the company was part of the, now no more GEC Group of companies. Not to be confused with the American GEC Company.

Our enthusiastic and knowledgeable presenter Andy Cardy after a brief overview of the long standing and successful JM Axial Flow Fan range introduced the new JMv range of Axial Flow Fans. The first phase of this range is from the 315 to the 630 dia. mm. Larger diameters will be phased in over the next few years and regarding legislation issues there is a four year time frame, up to 2020. It was explained that there are many fan manufacturing companies large and small and FW has always been high in the leading pack or even the market leader regarding its expertise, product design and innovation. However, whilst this tends to remain the case in general it is not as prevalent as it used to be and have been overtaken in some areas. Together with the rate of change with international regulations and the current focus on cost, environmental and fan efficiency issues the ever changing market place had to be satisfied if FW was to remain at the top.

The presentation introduced how the company went about the redesign process, the types of technical tools used and the advantages of such tools e.g. CFD (Computational Fluid Dynamics) and as part of the overhead display demonstrated in brief how this worked and what could be understood and achieved by its use. A key component of a fan is the design of the fan blade and this was redesigned to give greater twist to it with some small trailing blade edge tabs all of which was to remove the air from it more quickly and came under the heading of VCC (Vortex Creation Control).

The overall programme came within what was / is referred to as E³= environment, economical and expertise. There are two factors that impact the environment that is by using less electrical energy and using fewer raw materials in the design so the carbon footprint is reduced. In fact since the product launch so far the estimation is that the equivalent of 57K aluminium drinks cans have been saved. Regarding the economical factor the product costs less to operate whilst maintaining its functionality and of course there is the expertise of the company. Both motor and fan efficiency have increased and in some instances surpassed expectation and more is still to be gained. By the end of 2020, the legislative time frame the range will be completed.

In the Q & A session following the presentation Andy was asked how many types of fans would be covered in the product range. He explained this was not an easy question to answer because a fan can have many combinations and permutations depending upon customer need, size, operating characteristics, and operating environment etc., there is not necessarily a standard model. The answer given although not a surprise to the author was he thinks a great surprise to the audience. At the last count there was over 1M combinations and permutations.

Following this interesting introduction we were split into four separate groups and made our way through the factory for a tour of the Development Laboratory. During the transit from the conference room we travelled through the factory and were shown areas of manufacturing and assembly interests. In the Dev. Lab. which included an Anechoic Chamber (which is not something that exists with all fan manufacturers) we were shown how fans were tested for certification purposes and customer witness testing, the relevant criteria for deciding fan performance and what is meant by certification. The engineers in here were most patient and informative. The final part of the visit was to the Engineering Department where we were shown demonstrations of fan design using the actual computer technologies in action as has been previously mentioned which as would be expected encouraged a number of leading questions and comment. Again thanks must go to the time and patients to the participating engineers. A very interesting and informative afternoon concluded with a group photograph.


Bob Barnett.



Visit to SITA UK (SUEZ) Waste handling - Ipswich Monday 14th June 2016


What do you do with 260K tonnes of house hold and business waste generated annually? Simple you burn it. Easy to say difficult to do when there are stringent emission limits and standards to conform to, rigorously enforced by the Environment Agency and usually facing adverse public opinion. Nevertheless, it is an established and accepted fact that the community cannot continue to fill large holes in the ground with its rubbish.


Well on the appointed date 20 members (and the bookings went very quickly) gathered in the conference room at the Suffolk energy-from-waste facility at Bramford, Ipswich. We were welcomed by Emily Pike, the Community Liaison Manager and given an overview of the whole project, which remarkably for this type of facility only took about 4 years and has only been operating for about 2.5 years. The speed of this project as explained by Paul the Plant manager and Emily was the communication transparency between all the interest groups in the local community, Suffolk County Council (SCC) and SUEZ which proved to be very successful and achieved all the objectives.


he location was previously a large SCC site in a semi industrial area and the £180M construction came in on budget and on time with an exemplary safety record. During the construction phase more than 100 Suffolk firms were engaged on the project earning in the region of £13.5M. From a local perspective it is estimated that about £1M is generated annually by the plant for the community by way of providing employment, something like 75% of the 47 employees come from the local area and had to be specifically trained and taught new skills. Then there are support services and various contractors.


The Architects Grimshaw are English and designed the Eden Project, the technical design of the plant is French by CNIM, and the furnaces and moving grate system is German. These two latter companies have the technical knowledge and expertise for these types of undertakings having installed many of these facilities. It is disappointing that there are no similar UK companies but all the steels and civil engineering was of UK origin.


Incoming refuse freighters tip their loads into a very large holding bunker from where two overhead grab cranes each with a capacity of two tonnes grabs, lifts and loads each one of the two hoppers that feed the two corresponding furnaces operating at about 1000 degrees. In each furnace there is a slow moving stepped grate at an angle of 35 degrees on which the rubbish, under gravity moves down the grate whilst continuing to burn and falls as ash away from the grate on to a moving belt conveyor. The hot flue gases are used to heat water which in turn makes super heated steam and is used to drive a generator to produce about 25 megawatts of electricity, about 22 mw goes to the National Grid and the remaining 3 mw supports all the plant's needs. The whole process from start to finish is automatically controlled with every part of the process monitored from a control room with the staff having human intervention as and when needed. All gases are thoroughly cleaned and they finally pass through a particular type of special bag filter that collects any remaining fine particles. Only at this stage are the gases emitted to the atmosphere via two 81.5 metre tall flue stacks. As previously mentioned the whole process is continuously and rigorously controlled by the Environment Agency and the site operates well below the set limits. The monitoring of the ash residue being done 100% more than required. Ash is separated into metals this is disposed with for recycling, aggregates used in the construction industry and the fine particle ash (two grades) again used in the construction industry.


There are two visitor centres one mainly for children teaching with hands on examples all about waste, so of course some of us older children had to have a go and secondly live displayed monitoring of the process all of which enhanced the whole experience.

Since the site has been opened it has won several national accolades in different sectors from environmental to construction. The contract arranged between SUEZ and SCC is for 25 years at the end of which time the plant will revert to SCC ownership and they will have saved an estimated £350M compared to having continued with landfill. Truly a site worth visiting if you have the opportunity.

Bob Barnett