I have been to.. Fort Purbrook

Another day, another fort...😏

The weekend before last, with the tail end of Tropical Storm Bertha making her presence felt, and a forecast for rain, little'un (grandson) and I headed to Fort Purbrook to a boat jumble (think wargaming bring and buy but for sailing/boating folk - so similar levels of tat, at similarly laughable prices, but the occasional nugget....). The bonus for me though, was the opportunity to have a look round Fort Purbrook which is one of Pamerstone's "Follies" built to protect the dockyard and harbour from a possible French invasion by one of the later Napoleon's (the third one to be precise)..

Plan/map...

The fort was one of six built on the edge of, and along the top of, a natural escarpment/hill that circles the north of Portsmouth called Portsdown Hill as a result of the 1859 Royal Commission (the same commission also resulted in the Spithead and other forts in the Solent). The development of rifled gun barrels (Armstrong, Whitworth etc) had made it possible for an invading army to bombard the city, which was just less than 5 miles away, from the same escarpment.

The forts replaced the old Hilsea Lines (which I must also visit!) which are at the bottom of the hill and were made obsolete almost overnight by those technological advances in artillery...


Purbrook is the most easterly of the forts, although there were a couple of smaller earthworks or redoubts built further east they are now long since gone.

By the by, the threat from Napoleon III was effectively over long before the forts were completed, but they were used as anti-aircraft gun emplacements during World War II.

A new phrase to me - and that's what I love about military history - this is a Caponier, or covered way, between front and main fort

One of the eight gun emplacements - following - these were designed by Captain (later Sir) Alexander Moncrieff - around his concept of the "disappearing gun" - basically the gun carriage enabled the gun to rotate backwards and down behind a parapet, or into this pit, protected by the wall after it was fired

Moncrieff gun pit

...this was taken at Fort Nelson along the hill - but shows what the fully functioning gun mount might have looked like...

The picture above is not I think as the actual guns would have been - it looks an older/earlier model - I did find this however, which is more as I would have expected...  my research efforts seem to indicate that this model of retracting gun was ordered for the forts...

Hideously complex set up - difficult to maintain and prone to mechanical failure - they didn't last long before being superseded by other methods of protection/hiding..

Following - looking across the fort (and the jumble!) in a north east direction - you'll note openings in the embankment between the gun pits - I'm assuming these are either covered ways back to the main fort (ie. underground), and/or for ready use ammunition...

The gun pits had a selection of artillery types left laying about - clearly iron - most stamped VR = following is interesting - the one second right looks like it's been re-bored, or re-lined?

Following - a close up of the smaller barrel in the above - it looked to be in better condition, and I was quite surprised as it appeared very small - anti personnel weapon for close defence?? Any ideas what the markings mean - I've searched but can't find anything....  I'm guessing the 6 is for 6pdr?

Taken from the top of the embankment looking north - so in effect the forts are protected by a deep glacis - from the bottom of the hill this ditch and counter rampart would have been an unwelcome surprise for any attacking force...

Following - a view of the front of the fort looking south - that's the dockyard you can see in the distance..  the main entrance the fort is just to the left of the blue van - you can just see the caponier far right...

Following - more detail of the Moncrief gun emplacement - the top of the surrounding wall is about 8 feet

Following - "front" (back??) of the fort - this is the south facing side...

Following - detail of the ditch, or moat - there's a significant amount of brickwork there!

Further reading:

http://www.subterraneanhistory.co.uk/2008/10/fort-purbrook-portsmouth.html