Evans Water Engineers


+44 1566 782323 · www.evans-engineering.co.uk · email sales@evans-engineering.co.uk


EVANS History


EVANS ENGINEERING is continuing a long family tradition in water engineering going back to the Industrial Revolution. Joseph Evans started an iron founding business around 1810 and possibly earlier in the ‘Forest of Dean’. By the middle of the nineteenth century Joseph Evans and Sons were manufacturing an extensive range of water pumps for domestic and industrial purposes, and by 1900 they were manufacturing and supplying steam pumps to mines, and industry through out the world. They also manufactured the famous ‘Pickering’ governor for steam engines, castings for AJS Motorcycles and pumps for the trenches in the Great War and operation ‘P.L.U.T.O.’ in the Second World War.

History of Evans EngineeringAfter the Second World War much of the business changed hands, though there are many pumps still in operation including an 1864 hydraulic ram in West Cornwall and steam pumps in an oil refinery near Baghdad. It fell to the next generation of Evans to continue the family engineering tradition, with James Evans being the prime mover behind the ‘LYD Project’ a full scale steam locomotive, and Rupert Evans moving into the design and manufacture of small water turbines.
Electronic Load Governing’ was one of the key developments that set EVANS turbines apart from the small number of firms that still built micro and mini hydro systems back in the 1970’s. The system of differential load governing’ was first employed by my father in 1949, but with the help of Gerry Pope of G.P. Electronics, it fast became the world standard for small-scale waterpower systems and won an ‘International Inventors Award’ in 1996.

Evans Engineering renewable energyGrowing concern about the environment, climate change and future energy supplies put us at the forefront of ‘Renewable Energy’ technology when almost all water turbine manufacturers had ceased trading or were no longer interested in small projects. We also helped to start many early projects with the ‘Centre for Alternative Technology’ and (ITDG) now called ‘Practical Action’. The ‘Electronic Load Governing System’ is to be found in over 40 countries around the World and has been widely copied!

We also pioneered the development of small vertical shaft Pelton turbines (very adaptable), open volute propeller turbines (fish-friendly), rotary backwashing screens and a host of other innovations detailed in our ‘Innovations Section’ We continue to supply components, packaged plants and complete projects and our equipment is to be found in very remote areas where backup and maintenance is very difficult. In recent years a design for an improved watermill has been introduced to Northern India where many hundreds of units have already been installed. Several funding and development agencies were involved including the British ODA, World Bank, I.T. Power (India), and HESCO ( local rural development group).

Evans Engineering research and developmentResearch and development continues with a comprehensive range of modular micro-hydro turbines (‘The Armstrong’) offer a very flexible and efficient alternative to the more widely known ‘cross-flow’ turbines. Unusual projects have included one of the first ‘Tidal Stream Turbines’ tested in Scotland in 1997 that lead ultimately to the ‘Severn Tidal Reef’ concept being submitted to the UK Government’s consultants with the support of many environmental groups because of its potentially low environmental impact. Work is continuing on the concept, despite being hijacked by several of the countries largest firms of consultants and engineers!

It is said that a letter turned up amongst the old Joseph Evans office papers, from an Argentine farmer requesting a quotation for a ‘horse driven pump’ similar to one supplied previously to a neighbour, but slightly smaller “because his horse wasn’t as strong as his neighbours horse”! I am not sure it customising pumps around a particular horse on the far side of the world, makes good business sense, but it does show that at EVANS we try and accommodate the customers requirements if at all possible.


EVANS Mission

Evans Engineering missionI aim to continue the long family involvement in the water industry in all its ramifications. What started with water pumps in the early nineteenth century has progressed into small-scale waterpower equipment around the World. The environmental, political and social aspects of sustainable energy production and water use, have grown in importance over the years. We see ourselves as pioneers in the design and promotion of technology that will reduce environmental and social conflict over water. We have won numerous awards in the field and aim to expand the business rapidly over the next five years for our bicentenary.


The foundation for the business over the last thirty years has been to:

Evans Engineering equal opportunitiesEQUAL OPPORTUNITIES

I endeavour to support anyone, regardless of gender, race, age or disability to pursue aims that are consistent with our main mission. As a disabled person I am fully aware of the institutional and cultural barriers to those in a similar position to myself. We have always had multi-cultural collaborators around the World and employed an above average number of women for an engineering business.


Whilst endeavouring to meet all statutory requirements regarding safety, I aim to cultivate a safety conscious workforce who think for themselves rather than expect a safety officer to tell them what and how they should do everything. Much of the work is carried out alone or in small groups, so attention has to be paid to potential hazards and emergency procedures. Safety instruction is given whenever possible and whenever appropriate.


On the job training, including safety training is given where appropriate. Employee and sub-contractors are encouraged to broaden and develop their knowledge so that their involvement with this business and the industry is a long term endeavour.

Evans Engineering quality managementQUALITY MANAGEMENT

Waterpower equipment is required to operate unattended for long periods of time and the maintenance interval for bearing changes is often in excess of ten years. To achieve at least a thirty-year life with only minimal maintenance requires considerable attention to detail and quality of materials. Our solution has been to simplify the equipment when the budget is tight but to maintain the quality of the reduced number of components. Even with our 'agricultural' turbines for driving pumps and simple machinery that have no casing, the runner, shaft and bearings are of good quality. Our quality system has been developed over the years and is based on BS EN ISO 9001:2008 a copy of our Quality Manual can be made available on request.

EVANS Philosophy



Unnecessary complication only makes systems less reliable, and those with all the control functions vested in a single electronic component are particularly vulnerable. In the West we have come to rely on electronics, safe in the knowledge that a service engineer is just around the corner. In many countries and here in the future this security may not exist and only systems that have a very simple will continue to operate.


We live in changing times and the skills and components that we take for granted may become difficult to obtain in the future. With most resources coming under increasing pressure, it is ridiculous to design items such as hydro plant for a useful life of less than thirty years and I consider fifty years to be the minimum. We have one particular installation still working here in Cornwall, with equipment built by my great grandfather in 1864.


For too long mankind has relied on spending the ‘capital’ laid down in our fossil fuels, and now is the time for us to live within our energy means. Whatever your views on ‘Climate Change’, a ‘Wise Virgin’ should be planning to use something other than oil to light her way in the future.


Regardless of Government incentives that come and go and always have very expensive ‘strings attached’ in the form of regulation, taxes and intrusion, a waterpower project should give you a significantly better return on investment than putting your money in the Stock Market. The situation is somewhat less attractive if you are forced to borrow the capital at high interest rates but this may change with the introduction of a ‘green bank’ or funds specifically to provide the capital at reasonable rates.


The most successful projects that I have worked on over the years have been those where the owner has taken a real interest and pride in generating power from a ‘shed at the bottom of the garden’! It’s not too difficult or complicated, but it’s not as simple as switching on a light (and having to pay the bill). If you have the right kind of site, the resources to do it and a certain amount of perseverance, then I think you will enjoy doing what I guarantee will be an interesting and rewarding project.

EVANS Services

The fabrication shop is equipped to handle components up to 4 tons and completed assemblies of about 20 tons. The largest item we have built to date was a 1MW water turbine weighing over 40 tons with its gearbox, generator and valves. Our equipment includes a large Sedgwick folder, ‘Pulsed Arc’ MIG welding for stainless steel and aluminum and plasma cutting. Stainless steel is our preferred material for fabrication, being 3CR12 or Nirosta (11% Cr, 1.5% Ni). This gives a very competitive price against galvanised and painted mild steel, and several advantages including unlimited component size, no distortion and no repainting.

Evans Engineering machine shopThe machine shop includes a ‘Colchester’ lathe with hydraulic copying and a vertical borer with a capacity of 1400 mm. The normal range of drilling, turning and polishing equipment is also in place. Coded welding and presswork up to 400 tons can be arranged locally. Our own pattern shop and investment-casting department can provide components or complete assemblies.

Specialist Foundry Services includes large investment castings made from our own wax assemblies. Seventy kilograms (net weight) of stainless steel is the largest one piece casting to date but castings of over two hundred kilograms are feasible. Investment casting gives you a very accurate shape and makes polishing unnecessary for most applications. A range of metals and alloys can be specified to meet your particular requirements. Castings in carbon and stainless have been in use in our turbines for the last fifteen years. Our system of welding many components castings to make a large complex shape is both cost effective and reduces the difficulties of casting and subsequent polishing, since the latter is carried out prior to welding.

Repairing cast iron, the ‘backbone’ of traditional engineering, is an important skill we have developed over the years. Re-designing components that are missing or badly corroded or even wrongly designed in the first place, is all part of the business. Where high performance is required from an old machine, it may be feasible to install, for example, a totally new ‘runner’ in a pump or turbine that will give as good and sometimes better results than a modern machine.

Design and build is our preferred mode of operation, though we are happy to work to clients drawings and specifications Installation and commissioning of civil engineering steel work and plant such as turbines and pumps, are our normal business. Re-designing components that are missing or badly corroded or even wrongly designed in the first place, is all part of the business. Where high performance is required from an old machine, it may be feasible to install, for example, a totally new ‘runner’ in a pump or turbine that will give as good and sometimes better results than a modern machine.

The cost of replacing items of plant such as water turbines and pumps, simply because the manufacturers are no longer in business or providing spare parts, can be very high, and the modern replacement may be inferior to the existing item. Re-engineering such plant with modern bearings, wearing parts and refined design, can prove very cost effective, especially where the cost of having the plant out of commission is high. We have also been involved with the restoration of a wide range of Victorian and Edwardian engineering items including steam engines, watermills and water turbines. Restorations may be used for static museum display, so few if any of the worn parts need be replaced, or the machine may require a full overhaul to put it back to good running order.

Careful dismantling of old plant is vital if damage and additional expense is to be avoided. This requires both patience and knowledge of how equipment was manufactured many years ago, and our extensive library of Victorian books and drawings has served us well.

Evans Engineering Tidal Current Turbine The first ‘Tidal Current Turbine’ in the UK was built by Evans Engineering some 15 years ago and this helped to establish the whole marine renewable industry. Another more recent design is the environmentally friendly ‘Severn Tidal Reef’ www.severntidal.com that is subject to a number of investigations at the present time.

Rupert Armstrong Evans

Managing Director