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COASTAL DEFENCES - A Holiday Workshop by STEAM Powered Education

Updated: Nov 9, 2023

Workshop Objectives:

  • To learn about coastal defences through a presentation on the history of defences in and around Clacton

  • To build a coastal defence diorama

  • To visit some coastal defences in Clacton and Harwich

Beacon Hill Battery from the main Battery Observation Post overlooking the sea that it was designed to defend Harwich, Felixstowe and Ipswich from marauding invaders.

I first got the inspiration for a holiday workshop on coastal defences from a Peter Appleton, who works at Beacon Hill Battery. He came to the Clacton Historical Society giving a talk about the RDF station (Early Radar 1940) at the edge of Beacon Hill Battery.

Peter describing the machines that sent out the RDF signal and received it.

Peter's love of 'Historical Concrete' resonated with me as I have spent my youth exploring Napoleonic, first and Second World War bunkers, emplacements and tunnels in and around Brompton, Chatham, where there was a large naval base from 1547 to 1982.

Chatham/Gillingham is also where the Royal Engineers have their HQ and the Gurkha Engineers were based in Kitchener Barracks so it was full of underground and overground military emplacements to sneak into. Some holes would just appear in the ground and we would explore the old Napoleonic forts that were, ironically, built by the French Prisoners of War to protect Chatham from an attack by French Raiders. Fort Amherst, which is now open to the public was where a bunch of mischievous teenagers such as ourselves, snuck under the 'MOD Property, signs to climb down the 101 steps to the tunnels deep in the side of a chalk cliff.

The natural choice for a Coastal Defences workshop is also Clacton. Why? Well, it has been the obvious choice for would-be invaders for centuries. The Martello towers, strong thick walled egg shaped strongholds, were built between on the east coast of England between 1808 to 1812. Beacon Hill Battery was in addition to 'The Redoubt' which was like four Martello towers joined together. This was initially built in 1890 and had 6 and 10 inch disappearing guns. I have built an example (link below to FB site). The gun would fire, the recoil sending it back below the lay of the land and therefore ships would find it difficult to locate where they were being fired from.

This is an example of a 10 inch breech loading gun. As it fires, the power of the backward motion pushes the gun back and down so it can be reloaded below the height of the ground and therefore protected and hidden.

The day started a little later than expected with two less than expected. I spent the first half hour with a history presentation about invasion throughout Britain's history and focusing on the last two hundred or so years. Napoleon's victories across Europe prompted the Martello towers to sprout up all over Britain.

Next, we went straight into using the visualiser to help explain how to make the basic shape of the emplacement. There was a set of instructions on how to assemble the gun which was based on a Second World War 4.7 inch gun with a recuperator.

We also made Battery Observation Posts (BOP) based on a template. We used cereal box card to make them and made sure that the inside of the cereal box was on the outside so we could paint them. Below is the main BOP nicknamed the Dolls House at Beacon Hill Battery.

Next, we nailed wooden feet into the diorama bases. The skill of nailing was quite a challenge for the students. It was good to see the students learning a new skill.

After that, we stuck bits of polystyrene to the diorama bases and used a hot wire foam cutter to sculpt the polystyrene into cliffs and hillocks.

Lastly, we mixed plaster of Paris and we pasted it over the polystyrene to give a more realistic feel to the diorama.

The base painting of brown and green was next. Unfortunately, that was as far as we got before we ran out of time. There was one student who was able to stay behind and managed to paint the PVA glue and sprinkle some of the fake grass on them.

Additionally, we had another student who worked on it at home and brought it to show us.

We had a few other nearly finished dioramas including one with a bunker and BOP like the battery at Beacon Hill

After the morning making coastal defences, we then walked into Clacton to find the Martello tower F which was the only one with a moat around it. The owner, Paul Nash, was very kind in giving us a private tour. Usually, it is a cafe and grounds but wasn't open on the day we chose for the Holiday Workshop. There are a few ghost Stories related to the tower. One of them is that two little boys walk around. Paul managed to show us a grainy picture of two ghostly images of boys. He also explained that once he heard them running around when he was all alone in the tower.

Martello towers are egg shaped with the pointed bit facing the sea. The walls are very thick. At the base, they are fourteen feet (4.3m) thick. They first became an adopted design in Britain when Horatio Nelson was fighting the French in Corsica. He noticed that all of the cannon balls were bouncing off the French towers called a Martello.

This is a picture of the front of the Martello tower 'F'. Notice that this is the pointed end of the egg shape so that cannon balls, directed from the sea at the tower, can bounce off the thick curved walls.

This is down in the base part of the Martello tower. Apparently, there are 750,000 bricks in the tower and the base walls are 14 ft thick. Because there was no entrance from the moat, a group of scouts spent months digging an entrance through the wall to the moat garden.

This is the moat and bridge to the main entrance. The last part of the bridge is a drawbridge. you can just see the rusty chain dangling down on the pole that used to pull the drawbridge up. Getting it working again would be an excellent STEAM project.

This view gives one a better idea of the shape of a Martello tower. There are four points for cannons to be mounted pointing in all four points of the compass.

Here we all are in the moat grounds of the fantastic Martello tower. Paul Nash was an excellent host opening it up specially for us to visit. Many thanks to him from all of us.


The view from the main Battery Observation Post (Nicknamed 'The Dolls House'). Below is the 4.7 inch gun emplacement and two 6 inch gun emplacements further back. You can see what areas they cover. The 6 inch guns could fire 7.5 miles which is beyond the headland you can just make out on the horizon. The positions are such that they just overlap one another's arch of fire.

Here we are in the magazine and soldier waiting area tunnels with Barry, the owner of the site, on the left explaining the various passages and tunnels.

Above, Barry is explaining how the pressure of the firing 6 inch gun needs to have vents built into the concrete walls to release the pressure. The bolts in the ground are the mountings for the 6 inch turret and gun.

The main BOP with some of us up in the top floor. There was a perfect view of Felixstowe and the entrance to the estuary.

Some information about the Doll's House.

A view of the whole battery. At the top of the picture you can see an anonymous looking building shaped in a hexagon. This is an early Radar Station. It was used to range find as an enemy ship entered the manually operated minefield. Once the range was found to be above a set of mines, they were manually set off (four at a time) to destroy the ship.

Us in the RDF station as the British called it. Radar is an American term. This giant RDF station emitted a microwave beam through the walls of the building and across the estuary entrance. It had a range of only two miles. If you stood in front of it whilst it was operated, you would be microwaved. The operators altered the direction manually from the room below.

By the middle knuckle of Peter Appleton is the RDF station. You can see the beam of the radar marked in black lines. Naturally, the beam could sweep left and right of this. The white dots are the mines operated by Beacon Hill battery, the black are those operated on the other side of the estuary by Langford Fort. The brown 'L' shape is the main channel for shipping. Apparently, the German bombers dropped mines in the main channel which sank a destroyer, HMS Gipsy, which drifted then sank just at the edge of the channel. You may be able to just make out where she sank from the orange mark on the inside of the bend of the 'L' of the main channel.

The room below the giant radar. This is the operations room where they interpret data from the received from the radar. There were a total of 8 men and one officer living in the RDF station.

Down in the lower floor where the crew quarters were, we ate our lunch. Here, a student is wearing an RNVR helmet. The crew of the RDF station were Royal Naval Volunteer Reserves (RNVR) so they would have worn these when in action. There were many RNVR personnel in those days, as the Royal Navy had hundreds of ships. Nowadays, we only have 19 service ships. In war, we wouldn't have that many RNVRs to rely on now.

The front part of the RDF transmitter/receiver. Originally, radar was an idea to create a weapon that would kill enemy with a sort of death ray. In the research, they realised that there were far better uses for the emitted microwaves such as range finding on enemy targets. The microwaves couldn't be made strong enough to kill at any range. Peter Appleton found the skeleton of this RDF structure just lying behind the station. He reconstructed it and added what he could to make the whole thing come to life again. Apparently, as this was a sort of experimental RDF station it only operated from 1941 to 1943. The site was decommissioned in 1956 with most of the equipment taken away. Peter has dedicated his life to restoring this station and Beacon Hill Battery.

Father and son looking over the estuary at Felixstowe. The view in front of them is the entrance to the estuary where the manually operated mines were laid. Apparently, after the war, they had to explode the mines in sets of four to dispose of them. That must have been quite a show!

Us returning on the minibus. A special mention to David our minibus driver. Tendring Community Transport provide excellent value for money because their drivers are volunteers. I can't thank David and all the other volunteers enough for giving us the chance to go on these valuable visits.

LESSONS learned

Once again, I tried to pack in too much. The dioramas were mostly but not completely finished. The dilemma I have is keeping costs down whilst packing in a worthwhile activity. I could have offered more over two days but would have to charge more making it less attractive to parents.

At the moment, I am not sure what to do about this except have it over two days but charge less for the second day. If I had half days then out door activities in the afternoons that might work well. Having a full day 9-3pm of indoor activities is too much for the children.

I also could have made instructions on how to make the turret and diorama. I ran out of time as I was juggling a few other priorities at that point in my life. Next time, I will make sure all of my instructions are in place.

I really enjoyed the visits as I see that this is my preferred balance of activities. A morning indoor STEAM activity and educational presentation and a directly related trip. I am proud of having achieved this and am really looking forward to the next workshop.

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