While we were in South Wales they mounted a gun aboard. As we were deemed to be a peaceful organisation the gun was said to be only for self defence, and it was mounted on the poop so that we could only fire it at any other ship that was pursuing us with hostile intent. With our polyglot crew there was difficulty in selecting a reliable gun crew. I was placed as gun trainer and the Chief Mate went to Cardiff for a two day training course so that he in turn could teach us. There was no time to test the gun before we were outward bound again for Milford Haven, to join yet another convoy. We were off to sea again still with our "new" weapon untested. We found the date 1918 stamped into the barrel to show that it had been made for use in the last war and had never been fitted or used.
After we had our four days of escorted convoy the ships all parted company, and we all went our separate ways, and some went quicker than others and were soon over the horizon. When we were properly on our way to the Southern hemisphere we were able to set about testing the weapon of self defence. The guns crew of the different nationalities had become familiar with what was supposed to be done, and after we had done another drill we loaded a live shell into the breach. To be on the cautious side we connected the firing lanyard to an extended signal halyard and all hands retired to the other end of the ship. The Captain had a last sweep round all horizons with his binoculars and when he found no other ship in view he gave us the signal to fire - which we did. All seemed to be successful. We decided to fire another shell off to prove that all things were well, and after the proper drill we re-loaded and the Mate put on an extra bit of elevation, and after retiring to our places of safety the Mate pulled hard on the signal halyards. The attached firing lanyard fired off the missile which went roaring through the upper air, but none of the watchers saw any splash of landing. We wondered if some innocent ship over the horizon would think that it was being attacked, or even whether our shell would go right round the earth to complete a circuit and catch up with us on its return.
By Christmas Day we were about level with Pernambuco in glorious weather. When we got a little further on we got the good news that the pocket battleship Graf Spee had been defeated by our light cruisers Achilles and Ajax after a battle off the River Plate. We had to put into Montevideo to put ashore our gun before we sailed into the territory of a friendly country and we saw Graf Spee resting on the mud with her decks under water where she had been scuttled by her Master Captain Langsdorf. The last time I had seen her was at Spithead for the Coronation Review where she had been greatly admired. If we had been a few days earlier we could well have been mixed up in that battle, and we could have turned round and attacked them from our rear.