How long did it take to reverse Titanic's reciprocating engines?

[Cam Houseman]

Lookup Stephenson linkage ... reversing steam engines.

Isn't it true that during her sea trials, it took Titanic at least half a mile to go from Full Speed to Full Astern and come to a complete stop?

 

[Jim Currie]

Isn't it true that during her sea trials, it took Titanic at least half a mile to go from Full Speed to Full Astern and come to a complete stop?

I believe so Cam. but that example cannot be linked to the accident, because while the steam pressure and propeller revs were falling, Titanic was under full left rudder. Those who have conducted hard-over trials have found that the ship's speed drops dramatically during such a turn - even with the engines still running at full. In the case of a 2000 ton ship making 14 knots, her speed fell to 7 knots before she completed a full turn. and the telegraphs were never touched.
You can bet that Titanic slowed even more dramatically due to her hull's forward motion being impeded while the engines were slowing down.

 

[Cam Houseman]

I believe so Cam. but that example cannot be linked to the accident, because while the steam pressure and propeller revs were falling, Titanic was under full left rudder. Those who have conducted hard-over trials have found that the ship's speed drops dramatically during such a turn - even with the engines still running at full. In the case of a 2000 ton ship making 14 knots, her speed fell to 7 knots before she completed a full turn. and the telegraphs were never touched.
You can bet that Titanic slowed even more dramatically due to her hull's forward motion being impeded while the engines were slowing down.

Meant to reply to this, sorry

So, even when Titanic's engines were set to STOP, she slowed down which restricted her ability to turn somewhat?

 

[Jim Currie]

Meant to reply to this, sorry

So, even when Titanic's engines were set to STOP, she slowed down which restricted her ability to turn somewhat?

Absolutely! It would not be long before the props stopped turning and before them, the turbine at 50 rpm. The latter was the prime activator in the flow across the rudder. In a short space of time. all three would be dragged at speed and create enormous turbulence around the rudder. This has been argued over before.

 

[Cam Houseman]

ah, thanks Jim, much appreciated!

 

[Kareen Healey]

Meant to reply to this, sorry

So, even when Titanic's engines were set to STOP, she slowed down which restricted her ability to turn somewhat?

I know I'm have an article about ship's reaction with physic of fluid (Archimede theory) and I while writing this the right article just crossed through my mind for I read this one week ago, fortunately. I will try to post it here maybe in a while, or maybe tomorrow. It is so instructive and they explain exactly why the ship slows down when it turns.