Extended Defence Officer Post (XDO Post), Hamble near Southampton
The village of Hamble lies on Southampton Water and has some interesting Second World War history, some of which is still visible to this day. These include two Extended Defence Officer (XDO) Posts.
To the casual observer these might appear to be gun positions but were much more than that.
One of the Hamble XDO post bunkers is on public land which anyone can walk right up to. The second XDO post is on private land but can still be seen from the beach when looking up at the bank.
My photos on this page only show the one on public land. You can also see more in this video I produced with my son shown below.
Photos of the bunker
The you see in my photos here is the bunker on publicly accessible land beside the Solent Way footpath. It’s situated midway between Hamble Oil Terminal and the Royal Victoria Country Park, just off Westfield Common.
The entrance and large observation slot (as shown above to the right) have been bricked up and it has been heavily graffitied.
The role of Extended Defence Officer Posts in WW2
This large concrete bunker on Hamble shore was designed to control the minefield operations on Southampton water. Mines were laid under the water to help protect the approaches into Southampton up The Solent.
I believe these would have been remotely controlled minefields.
In the XDO post at Hamble (sometimes referred to as EXDO posts), the operators could keep watch over the water and would manage the minefields, activating them if they had been needed.
It wasn’t just the waterborne mines in The Solent they would be responsible for though. Other duties and responsibilities included the control of anti-submarine measures. This would have been keeping watch for activity, but also possibly controlling nets and booms in the water.
They could have also listened for enemy activity with hydrophones.
The post’s position would also mean the personnel could advise other military units that were in the local area such as coastal defence batteries, heavy anti-aircraft units, and airfields.
The design of the Hamble XDO post bunker
Second World War XDO posts were designed to offer:
- A position of good natural visibility and so a design which gave a maximum overview of the sea.
- Enough room for the manning unit to function efficiently.
- In most cases the ability to be self-defensive if necessary.
The Hamble XDO post in my photos certainly ticks those boxes, particularly with the narrow observation position on the top which offers 360-degree observation.
You will also notice how thick the walls of the XDO post at Hamble is. This was to protect the concrete fortification as thicker walls, offer more protection.
This Hamble bunkers would also be used for defensive measures too. The XDO post would have been used to protect the minefields and support any defence against an enemy invasion of Southampton waters.
The slot that has been bricked up would have been used for firing from.
There is a report into the mining of water in the Southampton approaches in the National Archives called “Operation JSA”. I will try and see if I can get access to this report soon as it should shed more light on the WW2 XDO bunkers at Hamble.
In terms of any other references of the local XDO post bunkers and Southampton minefield in use during World War 2, I found this one which I’ve quoted below:
In April 1940, Cecily Gould launched her Yarmouth One Design Anthea at her home port on the Isle of Wight. She had obtained a fishing permit and began to take advantage of this whenever her ARP duties allowed her to. However, one day she found herself in a dying breeze with a strong tide taking her towards a prohibited area. She dropped her anchor, but it didn’t hold and soon afterwards three sailors in a naval launch came alongside and told her that she had drifted over a minefield. Anthea was then towed back where Captain Merriman, the officer in charge of XDO West (Extended Defence Officer’s Post), was hosting a tea party at Solent Yacht Club. The episode had not escaped his attention and he apparently ‘shattered his guests by his ready flow of language’. Unsurprisingly, Cecily was immediately asked to surrender her fishing permit.Troubled Waters: Leisure Boating and the Second World War by Nigel Sharp
It’s an interesting tale of someone sailing over the minefield on the Southampton water, particularly the aspect about the officer in charge of the Extended Defence Officer’s Post.
Whether it’s referring to one of the posts at Hamble, I can’t say for certain
Why are there two XDO posts at Hamble so close together?
I don’t know the answer to this. It could be that one didn’t give the optimum view. It might be that Southampton water was so critically important that it felt two positions were necessary.
I will revisit soon and take photos of the second XDO post from a publicly accessible position and make updates with any further research.