Friday 21 September 2018

Flower-class Corvette chart house

As a child growing up in Liverpool, Nova Scotia, there were a number of similar garden sheds around the town - boxes with windows sitting in various backyards. I probably played in more than one of them over the years.

But these were no ordinary garden sheds - they used to be sea going structures. Not only that, but they used to be installed on the bridges of warships - well, corvettes anyway - small commercially -built ships based on whale catchers that were gerrymandered into submarine hunters and convoy escorts. 

Not a Tardis - this humble shed used to be a charthouse mounted on the bridge of a Flower-class corvette. This example has been restored and sits in front of the Queen's County Museum in Liverpool. 
The first batches of Flower-class corvettes came from the builder's yard with a short foc'st'le and a small chart house (also known as a compass shelter or "Asdic hut") on the open bridge platform above the wheelhouse. On the early RCN corvettes, this hut housed the ship's only compass - in contrast with the RN corvettes with their gyro compasses and multiple repeaters, it was a magnetic compass with no repeaters. Macpherson & Milner's "Corvettes of the Royal Canadian Navy 1939-1945" recounts that this made it impossible for the corvette's captain to direct a submarine battle from the open bridge while having direct sight on the ship's compass. Some ships had a monkey's island on top of the chart house, and judging from the many photos of early corvettes in the above mentioned book, the construction of the chart houses themselves might vary from ship to ship in terms of size and the number of windows.

The following photos show early Flower-class corvettes with their charthouses fitted - in fact, as these photos were copied from the memorial wall of the Royal Canadian Legion's White Ensign branch, I believe all of these ships were sunk with the charthouses still mounted.

HMCS WINDFLOWER - one of the original batch of Flower-class corvettes built for the Royal Navy in Canadian yards but taken up by the Royal Canadian Navy. The chart house is seen on top of the wheelhouse, and just behind the mast. Photo courtesy Royal Canadian Legion, White Ensign branch.

HMCS SPIKENARD in the original configuration, though with an early SW1C radar at the masthead. Photo courtesy Royal Canadian Legion, White Ensign branch.

HMCS WEYBURN. Photo courtesy Royal Canadian Legion, White Ensign branch.

HMCS LOUISBOURG. Photo courtesy Royal Canadian Legion, White Ensign branch.
The original batches of corvettes had a number of issues which were rectified in refits later in the war (assuming the ships survived that long), and later batches of corvettes were built from scratch with the modifications incorporated. These modifications included (but were not limited to) a longer foc'st'le (to improve seakeeping abilities among other reasons), moving the mainmast behind the bridge (to improve visibility from the bridge), and the removal of the charthouse - it was replaced with an open pilotage, as can be seen today onboard the only remaining Flower-class corvette, HMCS SACKVILLE.

Liverpool was home to Steel and Engine Products Limited - STENPRO for short (I've been corrected that it may have been called "Thompson Brothers" during the war). Later bought by Irving (and since shuttered and sold), this little ship repair yard (a short hop from the house in which I grew up) with its single marine railway, was active during the Second World War refitting corvettes - and not being ones to throw things away, the chart houses ended up in people's back yards, and some were still there 30-odd years later when I was growing up. 

I believe the small platform on the front of the chart house may have supported an RDF (Radio Direction Finder) antenna, although not all ships carried their RDF in this position. Many photos show it mounted more centrally on the roof of the chart house.

Along with the door on the aft end of the chart house is a small protrusion with a glass top - I believe this housed nautical charts so that they could be seen from outside without the chart getting wet in adverse weather conditions.

A view of the chart compartment from inside.

The museum was closed during my brief visit, so I don't know if it is known which corvette donated this particular charthouse - I wouldn't be surprised if that information has been lost to time. I'm just glad to see that at least one of these structures (along with some childhood memories) has been saved.


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