HMS Erebus/Terror lifting props

[Ric]

HMS Terror and Erebus were fitted with lifting props, driven by a converted steam locomotive engine, for their ill-fated final voyages. The props would only be lowered and fitted when needed, to avoid drag when sailing.

I have been unable to find any substantive information on how this mechanism might have worked.

What I have established is that the props were mounted in a sliding wooden frame which could be lowered down below the water line through a well. But then how would the shaft be engaged? Was it pushed through some sort of stuffing gland, until it engaged with the prop, and then the other end somehow attached to the gearbox?

It is quite difficult to imagine how such an arrangement could be seaworthy in a wooden square rigger as it would require substantial opening in the hull below the water line.

There are some fascinating videos of the wreck of Erebus on Youtube, but not enough detail. I do hope that they will eventually raise the wreck as it seems remarkably well preserved and in shallow water too.

 

[Old Bumbulum]

I take it you haven't been to see the SS Great Britain in Bristol then?
You can examine such a system in real life to your heart's content!

 

[Keith 66]

Alignment of lifting prop was probably the same as on HMS Warrior & the Gannet at Chatham. The lifting frame was mounted in guides fore & aft in a vertical well & the prop was mounted on a short shaft within the frame the front end of the lifting shaft had a coupling with a slot in it which mated with a corresponding tenon on the back of the main prop shaft that connected to the engine. As long as the engine was aligned in the same position the couplings were easy to line up.
As for raising it, then what do you do with it? There are many shipwrecks that could be raised but as soon as they are exposed to air they degrade & disintegrate really fast. The costs of looking after such a ship are horrendous and are only justified if of national importance.
To see what happens when a ship is salvaged with no conservation plan in place just google the Schooner Alvin Clark.

 

[langstonelayabout]

On a slightly related subject (but not the coupling to the propeller) might I recommend the book 'Erebus' by Michael Palin (yes, that Michael Palin).

Excellent book documenting the build, early life and various voyages of Erebus, her captains, crew and other significant people surrounding her, including some of the Inuits involved in the approximate location of the Wreck prior to the actual discovery.

I've just finished reading it (but you can't have this book as it's autographed by the author) and recommend you seriously consider it too.

 

[langstonelayabout]

HMS Terror and Erebus were fitted with lifting props, driven by a converted steam locomotive engine, for their ill-fated final voyages. The props would only be lowered and fitted when needed, to avoid drag when sailing.

I have been unable to find any substantive information on how this mechanism might have worked.

What I have established is that the props were mounted in a sliding wooden frame which could be lowered down below the water line through a well. But then how would the shaft be engaged? Was it pushed through some sort of stuffing gland, until it engaged with the prop, and then the other end somehow attached to the gearbox?

It is quite difficult to imagine how such an arrangement could be seaworthy in a wooden square rigger as it would require substantial opening in the hull below the water line.

There are some fascinating videos of the wreck of Erebus on Youtube, but not enough detail. I do hope that they will eventually raise the wreck as it seems remarkably well preserved and in shallow water too.

An easy way is to visit HMS Warrior in Portsmouth.

Then, after you've visited the engine rooms and the rest of the ship, ask one of the ship's staff involved with the mechanical exhibits. Just like I did.

The chap explained it really well and even sketched a diagram for me.

 

[Kukri]

“Up funnel, down screw!”

 

[JumbleDuck]

Yet another example was fitted to the Discovery, now in Dundee. Very little left, but good explanations shown.

 

[dunedin]

I take it you haven't been to see the SS Great Britain in Bristol then?
You can examine such a system in real life to your heart's content!

The Danish frigate Jylland also has this lifting propellor system. Worth a visit if in Ebeltoft, and some photos of the arrangement in the link below
http://global-mariner.com/index12Jylland.html

 

[Major_Clanger]

There's even less left of one of her huge panting beams. Some idiot chainsawed through it to facilitate public access, but it was nothing less than vandalism. Fascinating ship though.

 

[ffiill]

As I recall Nansens Fram whi ch also took Amundsen to the Antarctic and saw service right up to WW2 was fitted with one and can be seen in a Norwegian Museum

 

[Ric]

Alignment of lifting prop was probably the same as on HMS Warrior & the Gannet at Chatham. The lifting frame was mounted in guides fore & aft in a vertical well & the prop was mounted on a short shaft within the frame the front end of the lifting shaft had a coupling with a slot in it which mated with a corresponding tenon on the back of the main prop shaft that connected to the engine. As long as the engine was aligned in the same position the couplings were easy to line up.
As for raising it, then what do you do with it? There are many shipwrecks that could be raised but as soon as they are exposed to air they degrade & disintegrate really fast. The costs of looking after such a ship are horrendous and are only justified if of national importance.
To see what happens when a ship is salvaged with no conservation plan in place just google the Schooner Alvin Clark.

Thanks for the replies - lots of interesting reading and visiting ahead..

As for raising the wreck, the interest would be forensic, not commercial. The expedition took some 200 or so brass air-tight and water-tight message tubes which were intended to be left in land-based cairns as the expedition progressed. Very few were actually left on land and subsequently found. But given the Victorian RN's obsession for logging everything, it would not be implausible that a comprehensive log would have been archived in the tubes on the ships as their dire fate unravelled.

The wreck of the Erebus is not particularly deep (judging by the youtube videos and known bathymetry of the area I would say about 15m) but the wreck looks somewhat collapsed and would be quite challenging to penetrate with diving apparatus.