Patrick Wadsworth is a NAS member with an interest in metal ships whether they are above or below the water. Here, he shares his long-awaited hands-on steam ship experience aboard SS Shieldhall.

Towards the end of 2019, I attended a NAS course on metal ships that took place on the Steamship Shieldhall.  We had learnt about the different distinguishing features of metal ships and what those lumps of metal we see when diving UK wrecks might have looked like before the ship went to the bottom.  This course had included a cruise during which we had seen the various parts of the propulsion system working.  Having an interest in all things steam powered, I had loved being close to the numerous steam engines that drove things around the ship as well as the large marine engines.

Historical overview of SS Shieldhall on the NAS course

Shortly after this course, there was a NAS two-day experience booked with SS Shieldhall using their ‘Gold Experience’ as a basis.  Due to various circumstances this got cancelled, but I kept my booking open and intended to participate in the experience the following year.  Then COVID hit and after that abated, other commitments meant that my experience got delayed until this year (thanks to Shieldhall for putting up with my continual re-booking).

The experience is two days of working on the ship.  The first day starts with the boilers cool, and is mainly learning about firing the boilers and the initial raising of steam.  Cold boilers need to be heated gently to avoid thermal shock and this takes most of the day.  At first only one burner is used in each boiler but once 60psi is reached the second and third burner can be lit to rapidly increase the pressure.  Once the pressure starts to rise, the various steam mains can be gently warmed to avoid condensation and finally the main engines and other auxiliary pumps and engines can be warmed through. There is lots of watching pressure gauges and waiting for things to happen on the first day but also time to explore the ship and get to know the people who you are working with.  There are hourly records of steam pressure, burner activity, air pressure etc. to be made which allows a good understanding of the complexity of what appears to be a simple task.  At the end of the day the burners are turned off and the pressure slowly drops overnight.

The second day was the day of the sailing to the Bournemouth airshow.  Although the boiler pressure had dropped overnight it was not that low and within half an hour we had enough steam for the ship’s systems to come alive.  Again, everything has to be warmed through.  It is also vital to know roughly when the ship will need more steam as the boiler pressure must be kept below the redline but not allowed to drop too far.  This takes time, skill and expertise as turning a burner on is not an instantaneous activity due to the need to vent any residual gases for several minutes before an additional burner can be lit and then there is a delay while the water temperature and steam pressure rise.  Soon we were ready to sail and I went to help the main engine team.  Commands from the bridge are telegraphed down to the engine room and then the engineer adjusts the steam valve to give the desired speed.  Unlike a car, this means that there is a delay between a command from the bridge and the ship responding.  There are two engines and each has a dedicated team, responding to the commands.  Each telegraphed order is repeated back to the bridge via the telegraph and also shouted to an engineer who records the command in a log.  Once we were cruising, there were checks to be made of various lubrication points on the main engines, auxiliary pumps working etc…

I then got a chance to work on the bridge and steer the ship.   It was interesting to think how each department has to anticipate the needs of the next in order for the ship to run smoothly.  The captain asks for a change in speed which is telegraphed to the engine room.  They have to be alert to the request and promptly adjust the engine speed, but none of this is to any effect if the boiler room has not got enough burners lit to be producing enough steam.  Once at anchor the boiler room staff go back to carefully balancing the steam pressure, not above the redline but still enough to allow those auxiliary systems still working, to continue to operate.  This required about one and a half burners so there continual turning off a burner, watch the pressure drop a bit, purge the burner, light the burner, watch the pressure rise and repeat.  It takes experience.  And then our return sailing time was postponed and postponed due to the air display over running which meant that each delay required consideration of how to ensure there was enough steam when we finally sailed but not burning more of the very expensive fuel than was necessary.

It is a great experience. I met a lot of very welcoming volunteers who were happy to share their experience and expertise and let me have a go.  Yes, there was a bit of waiting for steam pressure to rise but I felt part of the team from the moment I went on board.  I learnt a lot about the difficulties of operating a steam ship as well as just how many steam engines you can fit on a ship!

A sweaty crew award Patrick his certificate!

If you would like to learn more about steam engines, metal ships or metal wrecks, look out for our Metal Wrecks course being held on the SS Shieldhall in 2024 with dives on the SS Camswan the next day.