13 Apr 2016

British Gypsum: Robertsbridge wallboard plant

The Plant Manager of the Robertsbridge plant, Mike Emson, introduced Global Gypsum to the plant and provided an interesting history of the site’s near 140-year gypsum production history.

Global Gypsum: “Can you give a brief history of the plant operation and current operating process at British Gypsum Robertsbridge?”

Mike Emson: “Gypsum was discovered at the Mountfield site, around 400m from the modern wallboard plant in 1873 under the aegis of the British Association for the Advancement of Science. On 15 May 1876 the Sub-Wealden Gypsum Company was formed to make use of the discovery.”

“In 1891 the name ‘Sirapite’, a word play on the ‘Paris’ from plaster of Paris, came in to use and on the 4 February 1903 The Gypsum Mines Ltd. was formed. By 1925 Mountfield had 14 kilns producing plaster and by 1931 1Mt of Sirapite had been dispatched.”

“In 1936 the company took a major change of direction when it was amalgamated with British Plaster Board Ltd (BPB).The new company opened the Brightling mine 4.7km away in 1963. Mountfield was finally closed in 1998 after nearly 125 years of operation, mainly due to the availability of high-quality flue-gas desulphurisation (FGD) gypsum.”


Aerial image of British Gypsum's Robertsbridge plant, which has been running since the 1970s.


“The current plasterboard plant was built in 1973, so it is nearly 40 now. It underwent modifications in late 2005 when a new PremierTech Chronos wallboard reclaim plant was commissioned. We recycle all of our own plasterboard waste and builder returns. The upgrade was part of the company strategy and increased the output capability of the plant.”

“At present the plant uses imported Spanish gypsum rock, mined rock from the Brightling mine and FGD to produce a wide range of wallboard. A third of our production is of heavy special boards like Duraline and Soundbloc, which uses the Brightling rock. We also produce standard wallboard, moisture-, impact- and fire-resistant wallboard and Plank, which is a type of gypsum floorboard. There are various combinations of lengths and callipers.”

“Recent investment at the plant has been focused on the building and its infrastructure such as warehouse roofing, river line diversion, a rail line upgrade, restoring part of our land back to woodland and various other safety and environmental improvements.”

GG: “What are the major markets that Robertsbridge supplies and how far away is product sold?”

ME: “We have five plants in the UK supplying plaster and wallboard to the whole of the country. Robertsbridge specifically generally supplies the south of the UK, including London. We supply materials to the major house builders, are strong in the commercial sector and in the repair, maintenance and improvement sector.”

GG: “Can you describe the plant’s health and safety strategy?”

ME: “Health and safety is a core value of the company and we are very proud of our safety record as the factory has gone more than six years and the mine more than 14 years without a lost time incident (LTI). Both the factory and the mine have achieved ‘Millionaire Status’ (awarded to plants achieving over 1 million working hours without a LTI) and the factory has recently been awarded a safety Diamond. The safety Diamond is a very prestigious award within Saint-Gobain for significant improvements in safety and sustained results.”

“We have excellent engagement with safety reps driving the action plans and challenging the standards and have worked recently with the HSE to drive improvements and have been recognised by the HSE as raising the standards within the industry. We are praised on its website.”

GG: “We understand that the plant made lay-offs in 2007 and 2009. What led to that?”

ME: “We have needed to reduce the number of employees in line with the plant and mine output but will increase when the market strengthens and more output is required.”

GG: “How do you see the UK gypsum market in the next few years and when do you think the plant’s rate of production could be increased?”

ME: “This is very difficult to predict. Our view is that the market will remain challenging for the next few years so we will continue to drive efficiency improvements and develop our people to ensure we are in excellent shape as a business for when the market strengthens.”

GG: “Indeed, times of lower capacity utilisation can be useful for upgrading and making changes to equipment. What changes (if any) are likely to be implemented at the plant over the next few years?”

ME: “We have a mature continuous improvement programme that drives out plant performance improvements but continues to invest in equipment in the right areas. We continue to focus on our people during the recent times of lower utilisation and continued our People Development strategy. We have developed some excellent leadership programmes that have yielded great success for our people.”

GG: “Thank you for your time.”

Stuart Oulds is the Quality and Process Control Manager at Robertsbridge. He kindly provided a detailed technical tour of the plant, giving a thorough overview of the board plant and how it interacts with the company’s Brightling mine.

Global Gypsum: “What is the philosophy regarding production at British Gypsum Robertsbridge?”

Stuart Oulds: “Our primary activity is health and safety before we carry out any other gypsum activities. We always make sure that we have the appropriate equipment, that procedures have been thoroughly checked and any associated risks minimised. To help take this to the next level we run the Safe/Unsafe Acts (SUSA) programme, which encourages discussion of safe and unsafe practices. If someone has seen a particularly safe practice, they make sure that they mention it to the person to reinforce that action and make a record of the conversation. If they see an unsafe action, they also have a conversation, in a non-confrontational manner, asking the person to correct that behaviour in the future. Those events are also recorded.”

“From a production standpoint, we make sure that all of our operators are well educated in their processes so that they ‘own’ the process. Operators in each area of the plant are responsible for maintenance of that area. If equipment is not looked after correctly, the only people that will have to work extra hours to fix it are those that didn’t maintain it in the first place. This methodology has a dramatic effect on the standard of maintenance and helps keep the plant running very smoothly.”

“Here (pointing to a notice board), you can see that the operators in the paper-feed area of the plant have decided to put up a board showing common problems they experience with paper and the appropriate steps to resolve these. No one said that they should do that, but they have found a way to educate themselves and their colleagues about their process. That is what owning the process is all about.”

“Going back to health and safety, all of the plants and mines in the UK that are operated by British Gypsum are listed under one HSE certificate. That is another major factor behind health and safety at the company, because an accident at one facility has the potential to halt production across our entire UK operations.”

GG: “Can you provide an overview of the process?”

SO: “Starting at the beginning, the Premier Tech Chronos reclaim plant, which was installed in 2005, is one of only three on the planet in that it can receive wet plasterboard from external sites and the building trade. We have around 500t of cuttings and other waste from our customers every week. We can re-process all of that and it goes to the kettle as a feed alongside the milled and/or FGD gypsum from our storage dome.”

“In the calcination area we have three 15t/hr mills and one 35t/hr kettle, which operates at 150°C. The reclaim plant feeds the kettle as well. Two of the mills are for mined gypsum and the other is for FGD gypsum only. We are unique at this plant in that we are the only plant that runs both types of gypsum through the same mills and kettles. Indeed, this plant has always been the most adaptable plant in terms of the business. Our sister plants always run more standard board types but we have the ability to change the line and make all sorts of nearly continuous changes. That also means that we are the first plant to get affected by changes in the market.”

“At the moment we run mined gypsum on two days and FGD on three days a week, which is unique across the global gypsum industry. At the moment the plant produces something in the region of 19MM2/yr on a three shifts per day basis. We used to have five shifts running nearly constantly until 2007, when we had to reduce the workforce by a shift due to the economic downturn. We had to drop down to three shifts in 2009 and since then the line has been run from 15:00 on a Monday to 16:00 on a Friday inclusive. The total capacity of the plant is around 36MM2/yr.”

“We convert the plant’s running parameters to switch between the two gypsum types. Some of the boards that we produce require impact, fire and acoustic performance that the mined-based recipes give us but the FGD recipes don’t. For example, our Duraline-brand board, one of our top boards, has an impact rating, a fire-resistance rating and acoustic rating.”

GG: “Do you think that FGD will be able to accommodate those additional demands in the future?”

SO: “We are undertaking some projects at the moment within our technical department that are looking at making Duraline from FGD. That is one board that we supply the whole of the UK with, but at the moment it has to be made with mined gypsum. We have to look at issues surrounding the different crystal-growth characteristics of FGD gypsum and mined gypsum and also cross-contamination between the two types of gypsum. The FGD appears to impair performance in this particular type of board.”

GG: “How many types of board does the plant make?”

SO: “In total we have around 18 different motherboard types, which consist of a mixture of 3ft and 4ft boards. They are 9.5mm, 12.5mm, 15mm and 19mm calliper. We have a very full cutting list and that list is designed so that we can transfer over ‘on-the-run.’ We splice one paper onto another and just keep going. That is a quite unique feature of this plant. In terms of total boards we can produce around 761 types of specification board. We can also extend that to custom boards to suit individual customer requirements if need be.”

GG: “Can you provide a summary of the board line?”

SO: “The line itself is 440m long and we have three forming belts in a line followed by rollers. The board sets at around 300m and the cutter is at 360m. We can vary the line speed from 45m/min for our very heaviest board, which is 14kg/m2 to 90m/min for standard 8kg/m2. The board line was extensively refurbished in 2004, which saw its capacity rise by 30%.”

GG: “What monitoring systems does it have?”

SO: “We have a laser control system supplied by LIMAB, which is a profile system, and an Argos system to detect surface conditions for reject purposes at the far end of the process. The LIMAB system tells us the edge angle, calliper, width, cross-section and taper. The system is invaluable because it means that instead of sending the wallboard through a dryer for two hours to cook it and then realise that it is not up-to-spec, we can save energy by bringing pro-active detection up to the forming end of the line. We are not interested in drying boards that we then can’t sell!”

“Speaking of the dryer it has 12 decks in it, but obviously it starts out as just one deck. The temperatures in the dryer are critical for board formation and are set at 200°C in zone 1, way above the calcination temperature. Zones 2 and 3 typically run at 180°C and 100°C respectively. The dryer also underwent an overhaul in 2004.”

“The stacking operation, which uses Grenzebach equipment is also quite complicated and critical to the smooth running of the plant. We have two take-off legs for product as well as one for rejected boards. The product legs go to our warehouse, which is actually within the plant. We have to be very careful with dust as a result and have two dust-suppression units between the end of the board line and the warehousing area to make sure that sitting boards don’t get dusty.”

GG: “How does the plant interact with the gypsum mine at Brightling?”

SO: “In the past two months we have actually built a Performance Team Office within the plant. One of its jobs is to interact with the mine to keep them up-to-date with developments at the plant that may affect their operations. The company is very interested to keep everyone on both sides up to date while recognising that everyone can’t be an expert on everything. We have to maintain the skills and talents of the workforce, even if those skills are not critical at the moment.”

“That sort of approach is why this plant, one of the oldest in Saint-Gobain’s European operations, is also its most improved plant. This plant is in a strong position based on our improvement and the fact that we are able to develop people. Saint-Gobain is a true team effort.”

GG: “Thank you for your time.”

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