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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.
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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.
David Forster opened his talk with a short video illustrating ice production from the lakes in North America indicating that in the early 1800s this was where most of the ice used in UK Country Houses to keep food edible came from. A significant proportion was also imported from the glaciers of Norway. Once cheap ammonia became available it became possible to manufacture ice locally at much lower cost and much bigger volumes than importing it from abroad. Indeed as David indicated, this enabled deep sea fishing fleets to load up with ice and keep their catches relatively fresh for several weeks. One of the reasons why Davids Great Grandfather to choose Lowestoft as the base for his ice factory.
The ice was made by putting clean water into enclosed copper containers that were dipped into a cooling tank that was held at -10C by evaporating ammonia through a brine dissolved Calcium Chloride solution. The cooling tank at the Lowestoft ice works was the size of a public swimming pool. The containers, unless some specialised ice blocks were being formed, contained about 50Kg of water. It took about 12 hours for the water to freeze and a normal batch consisted of 50 containers. Once the containers contained solid ice they were taken out of the freeze mixture and the blocks of ice released for processing; some for domestic use but in the case of Lowestoft works the bulk by the fishing industry.
Having outlined the overall process of ice manufacture David then went on to describe how these various stages of the process were actually achieved. He spent some time on how the ammonia was compressed and what equipment was used in the process. He stressed that in the early days the factory was very dangerous because a lot of the equipment was driven via belts from a central drive shaft.
With the invention of closed cycle refrigerators the need for bulk ice production fell away rapidly in the late 1960s and by the mid 1980s the Lowestoft works had become uneconomic and were sadly closed. It would have closed even earlier but for the fact that by slight adjustments in the freezing process sizeable blocks of clear ice could be made; the blocks were big enough for use in ice sculpture. The Lowestoft factory was the ice source for the sculptures at the wedding of Princess Diana.
David finished his talk by outlining some of the projects he had been involved in since the closure of the works such as converting an redundant water tower into a house and the restoration of an old railway carriage.
Stuart Catchpole of Space East opened his talk by explaining what Space East is and how it came to be. It is one of the regional clusters that was envisaged when the UK government set out in its strategy for the Space Economy in 2021. There are 14 such clusters; some university based and some regional. Space East is based in Ipswich and is hosted by Suffolk County Council but its remit covers the whole of East Anglia. The idea of a cluster is that it tries to maximise the local potential in the space technology in the region. The UK Space Agency has also designed the clusters so that they can also work together if so required. Stuart then went on to talk about some of the major projects being developed in East Anglia. He indicated that the projects could roughly be split into two groups; inserting satellites into appropriate orbits and secondly using them to perform specific tasks.
One such area is in satellite technology. One such example was that of a Cambridge based company that is developing an infra red telescope that will be used to scan the earth surface via low earth orbit (LEO) satellites. This is potentially of great interest to the agricultural industry. For example these systems can be used to detect the early onset of heat stress in crops and the need for irrigation. And of course, the security and defence organisations are very interested in the technology, because of the low latency of LEO orbits motion, object movement can be detected even in adverse conditions such as smokey or foggy conditions.
Another big user of satellites in East Anglia are marine agencies, such as the Centre of Environment Fisheries and Aquaculture Science(CEFAS), based at Lowestoft. CEFAS use remote sensing to monitor fish stocks and marine blooms particularly if these are linked to drinking water supplies.
Another project that Stuart talked about was a Norfolk based company that was using satellite technology to extend the conventional line of sight control to enable their machines to fly much further so that they can be used to monitor the behaviour of marine wind farms and instigate robotic repair if required.
A very important part of many space applications is the need for high spec high reliability cameras. Stuart told us about Teledyne, a Chelmsford based company, who have been involved for the past couple of decades in designing and manufacturing space cameras including those on the Hubble and James Webb satellites. They are at the forefront of the development of state of the art new cameras.
This event was held at the Town Close School in Norwich and was attended by Society Members and friends as well as past members of previous Town Close Teams. Interesting contributions were also made by representatives of a nearby competitive team - Langley School.
Matt Buck, the event organiser from Town Close School, opened proceedings by explaining what the Greenpower Charity was and how his school had become involved with the electric vehicle aspect of the charity particularly the F24 events because it would involve a sizeable number of pupils working together as a team covering a wide range of skills such as engineering design, hands on construction and planning. The F24 was chosen because it came in a kit form with a basic frame and power source. Teams competing in this category had to conform to the kit dimension and underlying structure and the motor and battery unit were supplied with no substitution being allowed. Otherwise the teams could do what they thought best with the vehicle.
The basic competition was to see how far a given vehicle could go within a given time period of 90 mins on a fixed length enclosed track such as Goodwood or Silverstone or the Lotus test track at Hethel. All drivers had to be 13 or under and there had to be a minimum of 3. No adult could assist in anyway in driver changeovers.
This choice of vehicle allowed his youngsters to come up with all sorts of views as to how the car could be improved such as stream lining the car body without adding too much extra weight. They found that flax based light weight board could be moulded into a stream lined shape for the body and that ceramic bearings for the wheels axles significantly reduced friction. The team also found that keeping the motor from overheating was important and commissioned a suitable heat sink to be manufactured by a parent. They also found that batteries needed to be looked after i.e, kept at about 25 C and charged and discharged in a given way. Another important area that the teams discovered over the years was team work: particularly in the driver changeover sequence. It also turned out that driver training mattered particularly as this was more about vehicle handling in a non energy wasting sense than direct driver on driver racing,
One of the highlights of the evening were the contributions by Tessa and Theo, previous members of the Town Close team. Now no longer team members as they have both moved on to Senior Schools. They each described in outline how they had participated in the team but both stressed that being in the team was not only highly educational but also fun.