Welcome to NES 2024-25

Our Mission

Welcome to the Norwich Engineering Society, an active forum dedicated to fostering the exchange of ideas and experiences among all those passionate about engineering — past, present, and future.

For over a century, we have focused on the people behind groundbreaking innovations and their visionary concepts. Our mission is to enlighten, support, and develop our members in Norfolk and beyond. We achieve this through unique engagements, dynamic events, informative seminars, and insightful publications.

By championing the diverse disciplines within engineering, we ensure its continued evolution and relevance in an ever-changing world.

Off the Grid

A small group of 8 members assembled on Thursday 18th September to explore the off-grid power at NES member Philip Williams’s house in Halvergate Marshes.

Philip kicked off with the history of how he and his wife Julie ended up buying a house with no mains electricity, no phone connection, surprisingly with mains water, in the middle of nowhere. It did however have a diesel generator. The house itself was in a bit of a poor state, but you wouldn’t know it today, which is testament to the hard work and investment that they have put in over the years.

Philip then showed us the wind turbine in his garden which sits atop a 9m mast, generating a peak of 6Kw. It was whizzing round on the windy day that we visited, helped by it’s south westerly location and a lack of obstruction by buildings or trees.

Next we had a quick look at the solar panels on two sides of the roof of the house, a fairly common feature these days.

Then we got to the really interesting part – first of all a shed with 30Kwh of lead-acid batteries. Philip described in detail how these worked and showed us the mechanism for adding distilled water to all of the batteries from a single point. In the next shed was – Philip’s workshop, which apart from a neatly arranged array of tools, contained the somewhat elaborate controls for the wind, solar, oh and the 16.5 Kva diesel generator, which kicks in automatically when the batteries fall below 30% charge. Philip gave us a circuit diagram to look at while he described in detail the function of each component. One surprising element was a 6Kw resistor which is used to dump heat when the batteries are full and there is too much electricity being generated by the wind turbine – being off-grid means there is no opportunity to export the excess to the grid. It’s a nice headache to have too much energy! The main source of energy for cooking and central heating is by bottled gas, but every opportunity is taken to use the generated electricity.

Philip explained how, despite having mains water, issues with leaks between the fairly distant meter and his house caused headaches, mainly identifying where the leak is.

He also described the difficulties in obtaining a reliable and reasonably fast broadband connection. There is a BT line, but it is about 6Km to the cabinet, with no prospect of fibre to the premises. After years of experimenting with a variety of solutions, they have finally settled on cell phones and radio broadband, with the hope of 5g mobile reaching them some time in future.

If that whets your appetite and you are interested in reading more about Philip and Julie’s house, Philip has created an excellent set of web pages.

The visit concluded with tea/coffee cake and biscuits which Julie had kindly prepared. As is usual with NES events, there was extensive discussion of a never ending range of topics until it was time to go. Many thanks to Philip and Julie for their hospitality and a fascinating visit.

Tour of RAF Coltishall Heritage Centre

A group of 21 members and guests assembled on Thursday 7th August for a tour of RAF Coltishall Heritage Centre at Scottow Enterprise Park, Badersfield.

The tour itself was preceded by an excellent 40 minute presentation on the history of the RAF base, which was transformed from a potato field into a base for fighter aircraft, opening in June 1940. Following the end of WW2, with the advent of the Cold War, it was repurposed as a base for V bombers. It remained in operation for 66 years, finally closing in 2006.

Following the presentation, the group toured the site in convoy in their own cars, stopping for in-depth descriptions of various parts of the site, their original and current uses.

Part of the site is now a prison, which we did not visit! One of the most noticeable uses for the site is the massive solar farm, containing 200,000 panels sited on the grassy areas between the runway and access roads. It can generate up to 50MW of electricity on a good day.

We were told all about the buildings on the site, including the 4 hangers, which, following their original use for storage and maintenance of aircraft, are now used by an aviation company which mainly makes boats, a CO2 reclamation project, fabrication, a logistics warehouse and a bonded warehouse.

Next stop was to see the WW2 revetments (= structures, formed to secure an area from artillery, or bombing) which were used to protect Spitfires and Hurricanes. Remarkably these curved areas were still walled with original sandbags from WW2.

Next we were shown the Cold War revetments, which consisted of clusters of long walls of trapezoidal section which protected the V bombers from bombs, also separating the aircraft from the adjacent fuel bowsers. To simulate the conditions on the desert during the conflict in the Middle East, maintenance crews were accommodated in tents adjacent to the revetments, with field kitchens catering for their refuelling needs.

Finally we had a really close up inspection of a Jaguar aircraft, with an experienced engineer describing the function of all the parts of the aircraft and answering in great detail the inevitable plethora of questions posed by members.

There was still some time for those of the group who could tear themselves away from the Jaguar to visit the Heritage Centre, a unique collection of images, models and interactive displays. Members were welcome to return in the afternoon to view The Heritage Centre at their leisure.

Following the tour, a number of members and guests made their way to The Goat Inn at Skeyton for a splendid lunch, conversations over lunch ranging from archaeology at one end of the table to Rolls Royce Merlin engines at the other.

Former Atomic Weapons Bunker

A group of 21 valiant members and guests braved the elements (actually we were quite lucky, the threatened rain held off) on Saturday 19th July for a tour of Former Atomic Weapons Bunker at Gorse Industrial Estate, near Thetford.

The tour started with an introductory film narrated by Richard Maguire from UEA, explaining the reason for the site’s existence – the Cold War, the Blue Danube missiles, the V Bombers which carried the missiles, and design of the bunker. The site was designed to hold 57 missiles and warheads, however it was never fully populated, the intention being to make the Soviets think that we had more capability than we actually had in practice. The site was decommissioned in the early 60’s following the UK’s move away from airborne nuclear missiles.

Following that, Richard Eldred, the site owner, gave us a thoroughly engrossing tour around the site, explaining the various components and their function, ranging from the 3 large concrete bunkers which contained the Blue Danube missiles, the 57 locked and alarmed “hutches” which contained the fissile core of the weapons, stored clear of the high explosives in the missiles to avoid accidents, and the double layer perimeter defences, together with attack dogs, designed to keep intruders out. The Blue Danube missiles pack the equivalent of 15 Kilo Tonnes of explosive, which is similar to the bomb dropped on Nagasaki in 1945. Richard’s narrative contained endless anecdotes, including the story of how Richard’s parents bought the site in 1966, his father reputedly going out for a pint of milk and a newspaper, stopping by at an Estate Agents and returning home having bought a Former Atomic Weapons Bunker!

You may ask yourself – was this site a serious danger to the population of Norfolk? The answer is no, in terms of an accident at the site leading to a nuclear accident. However it could have been a target for any Soviet attack directed at Britain’s nuclear weapons arsenal. And now? You might be surprised to know that there is no trace of radioactivity above the normal background levels at the site.

After being purchased by Richard’s parents, the site was initially used to farm mushrooms, the darkness and even temperature of the bunkers proving to be ideal for the propagation of mushrooms. Unfortunately, after a few years a virus put paid to the mushroom growing business. These days the site is an industrial estate which is home to a number of small businesses, ranging from military surplus to engineering and paint spraying workshops.

At the end of the tour, a number of intrepid members made their way up (and back down!) the restored 25ft high watchtower.

Richard suggested Demon Core - The True Story (14 minutes) as an interesting video to watch. 

Ion Thruster

As Tim explained, his short talk at the 2025 AGM arose from a remark he had made in the Q&A session of the talk by Julie Black on Space Sustainability and Safety and Protection of the Environment (21-10-2024). In response to a claim made by Richard Aldridge that Ion thrusters could be used to power craft to move space junk out of the solar orbit, he had stated that this was not possible. Rather than take up valuable Q&A time arguing his case, Tim was persuaded that it would be a good topic for an AGM short talk. So here he was!

Tim opened the main body of his talk by stating that his remarks were based on what he remembered about solar system escape speeds. On reflection, he had overlooked that by being in orbit around the Earth junk only needed to be increased in speed to escape from the influence of the Sun from the orbit of the earth; about one third of the figure that he had in mind on 21st of October talk. He was now of the opinion that although an ion thruster could, in principle, escape from the solar system it would not be a practical way of removing space junk from orbiting the Earth. He intended to use the rest of his short talk explaining why.

Tim then described how the ion thrust process worked. In essence, an ion beam imparted momentum to its mothercraft by the impulse imparted during the ejection process. Even though the impulse per ion is very small, if enough of them are ejected at the same time over a long period of time significant changes in mothercraft speed can be achieved especially if heavy ions are used. Tim then went on to describe several examples of specific ion thrust driven spacecraft. All practical systems used Xenon as the ion source on grounds of relatively easy ionisation, high atomic mass and availability cost. The ions are accelerated by either electrostatic or electromagnetic forces; in the former case a neutralising electron beam is also needed to keep the overall beam neutral.

As Tim explained the limits to actual operation are the lifetimes of the ionisers, the amount of gas that the mothercraft was originally charged with and the nature of the energy source for the ionisation process. For example in the electrostatic thruster the lifetime of the electrodes producing the ion and electron beam is important to the time length of the ejected beam and hence the magnitude of the added momentum by the ejected ions. However, Tim concluded that the main limiting factor was the nature of the energy source for the ionisation process. For example if the source came from solar panels then the energy supply dropped as the mothercraft distanced itself from the sun. Tim concluded that even though , in principle, craft might eventually be capable of leaving the solar system using ion thrust drivers they would not be practical at removing the mass of junk that needs to be removed because the junk has to be regarded as a payload which reduces the effectiveness of any ion beam thruster.