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

[ryantimm92]

Does anyone happen to know the time it took for Titanic's reciprocating engines to go from a "Full Ahead" engine order to "Full Astern"? I KNOW that Titanic's engines were not reversed prior to the collision. My question is based solely around my curiosity of if the engine room crew were all standing at their posts, and an engine order was rang down to the engine room of "Full Astern" while the engines were going at "Full Ahead", how long would it take to execute that? Also, what was the absolute max RPM on the reciprocating engines?

 

[Frederik-Matthias Davids]

Hello,

Speed and Revolutions

Propelling the ship of dreams - What Do We Know About Speed, Revolutions, and Engine Orders?

www.encyclopedia-titanica.org

 

[Charles C. Deroko]

Good morning,

I guess the following has likely been studied in depth - but off the top of my head, the following few items might be considered:

• Stem 100+’ ahead of lookout, so perhaps1300’ + or so from stem to iceberg, about 1.5 x ship’s length
• 3 bells - time to react in wheelhouse, shift helm, rudder time needed to hard over & telegraph astern
• Engine room sudden alarm, location of personnel and reaction times to stations
• Time needed for browns engine to shift changeover valves
• Slow and reverse wing propellers
• Stated 37 seconds to collision with stated 22.5 knots
• Record of Olympic’s trials would offer insights to the timing of engine room sequence

Thanks,
Charlie

 

[Jim Currie]

Does anyone happen to know the time it took for Titanic's reciprocating engines to go from a "Full Ahead" engine order to "Full Astern"? I KNOW that Titanic's engines were not reversed prior to the collision. My question is based solely around my curiosity of if the engine room crew were all standing at their posts, and an engine order was rang down to the engine room of "Full Astern" while the engines were going at "Full Ahead", how long would it take to execute that? Also, what was the absolute max RPM on the reciprocating engines?

Here is the evidence of Trimmer Patrick Dillon who was actually in the engine room at the time
He did not see the dial of the engine telegraph but obviously noted the direction of the crankshafts.
-From Day 5 of the British Inquiry:
" They stopped.
3721. Was that immediately after you felt the shock or some little time after? A: - About a minute and a half.
3722. Did they continue stopped or did they go on again after that?
A - They went slow astern.
3723. How long were they stopped for before they began to go slow astern? A: - About half a minute.
3724. For how long did they go slow astern? A: - About two minutes.
3725. Two or three did you say? A: - Two minutes.
3726. And then did they stop again? A: - Yes.
3727. And did they go on again after that? A: - They went ahead again.
3728. For how long? A: - For about two minutes.
3729. Then did they stop the boat after that? A: - Yes."

 

[Elr James]

There's an earlier thread on this:

How much time between spotting of iceberg and the collision

Modern film and books have suggested it was as long as 30 seconds between Fleet's spotting the iceberg and the actual collision... Im inclined to beleive the collision occoured seconds after the berg was spotted.. I think Murdoch may have seen the berg the same time as Fleet, if not...

www.encyclopedia-titanica.org

Fourth Officer Boxhall testified that he heard three alarm bell rings from the Crow’s Nest and then heard First Officer Murdoch call out orders to Quartermaster Hichens to put the wheel hard over, and the noise of the engine room telegraphs ordering the reversal of the engines.

When live steam to a reciprocating engine (even a big one) is cut off, it stops pretty quickly and then the reversing mechanism is engaged. Take a trip on a Lake Geneva paddle steamer and you'll see how easily and quickly they go from ahead to astern. There's no question of 'crashing gears' or anything like that.

Having written that, at cruising speed in mid ocean, engineers are not normally on the control platform with their hands on all the levers in anticipation of frequent or emergency manoeuvring; so, an engine order being given and put into effect are two different things. Also, the time between any orders given and the Ship striking the Berg was just some thirty seconds, perhaps less, so it's probably reasonable to assume (as opposed to "knowing") that a reversal could barely have been initiated, if at all.

As to your actual question: in all honesty, I really do not know the answer: hope someone else can help and if I 'come across' anything, I'll be sure to let you know.

 

[Elr James]

Sorry: forgot to answer the second part of your enquiry. Full revolutions would normally be around 75 / 78 rpm (some 22 knots) up to maximum of 83 / 85 rpm (some 24 knots), although I'm happy to be corrected on that. The speeds would be attained including the use of the centre turbine of course: at around 165 rpm for some 16,000 shaft horse power.

 

[Stephen Carey]

Here is the evidence of Trimmer Patrick Dillon who was actually in the engine room at the time
He did not see the dial of the engine telegraph but obviously noted the direction of the crankshafts.
-From Day 5 of the British Inquiry:
" They stopped.
3721. Was that immediately after you felt the shock or some little time after? A: - About a minute and a half.
3722. Did they continue stopped or did they go on again after that?
A - They went slow astern.
3723. How long were they stopped for before they began to go slow astern? A: - About half a minute.
3724. For how long did they go slow astern? A: - About two minutes.
3725. Two or three did you say? A: - Two minutes.
3726. And then did they stop again? A: - Yes.
3727. And did they go on again after that? A: - They went ahead again.
3728. For how long? A: - For about two minutes.
3729. Then did they stop the boat after that? A: - Yes."

I doubt that a trimmer (lowest form of boiler room life) would know whether the engines were going ahead or astern by looking at them after only a few days on board, especially as the ER was not his usual station! I would have taken that evidence with a huge grain of salt...

 

[Stephen Carey]

Does anyone happen to know the time it took for Titanic's reciprocating engines to go from a "Full Ahead" engine order to "Full Astern"? I KNOW that Titanic's engines were not reversed prior to the collision. My question is based solely around my curiosity of if the engine room crew were all standing at their posts, and an engine order was rang down to the engine room of "Full Astern" while the engines were going at "Full Ahead", how long would it take to execute that? Also, what was the absolute max RPM on the reciprocating engines?

Here's a dit I wrote on Quora which explains some of the actions probably taken that night by the engineroom staff. It shows a parallel to the same situation I had 3 times whilst at sea and, whilst my experience is with motorships, they are reciprocating and direct reversing.
As to the engine revs etc., that's been answered in other posts here.

Why didn't Titanic just reverse its engine when it saw the iceberg?

Stephen Carey's answer: In the British Merchant Navy, to go astern whilst running ahead at full sea revolutions is known as a “double ring astern”. It’s only used when things are getting pretty desperate up top, as the usual way to avoid anything is to steer round it, as you do in your car or as ...

www.quora.com

Hope this gives an insight - it's just as unnerving these days as it was in 1912 - at full away on passage, it's not easy to stop or go astern very quickly, regardless of what was recorded on sea trials.

 

[Charles C. Deroko]

So this would suggest that the quick water from the turbine wheel was exerting a turning moment on the rudder. Based on the 37 second baseline determined from Olympic's post disaster turning trials.

Thank you

 

[Jim Currie]

I doubt that a trimmer (lowest form of boiler room life) would know whether the engines were going ahead or astern by looking at them after only a few days on board, especially as the ER was not his usual station! I would have taken that evidence with a huge grain of salt...

Why would you doubt such a thing, Stephen?
Sure, Dillon was just trimmer, but he had been an AB before that. He had done very little time trimming and spent most of it in the main engine room cleaning. This was his first trip below and you can bet he did not want to remain as a Trimmer so would have been watching everything.
I don't know if you have ever been in a triple expansion engine room, Stephen, but I most certainly have... very often.
Dillon would have to have been totally blind not to see when the "big ends" were slowing down...when they stopped and when they turned in the opposite directions during a maneuvering sequence such as he described. You do not need to see the telegraph unless you want to know the value of the order.
Just read your article.
You might like to know that back in the early 50s when I started, you got your head in your hands to play with if you rang down Full Astern from Full ahead without pausing at STOP. The reason given was that the boiler room had to be advised to stop stoking and dampen the fires to temporarily reduce steam production during changeover.

Oops! Re article - meant Charlie, not Stephen. Mia culpa 'nat. Oops! again...what am I doing...must be Scottish heat stroke!

 

[Charles C. Deroko]

Excellent, Stephen, thank you.

 

[Seumas]

I doubt that a trimmer (lowest form of boiler room life) would know whether the engines were going ahead or astern by looking at them after only a few days on board, especially as the ER was not his usual station! I would have taken that evidence with a huge grain of salt...

Actually, on the Titanic a handful of firemen and trimmers did work in the engine room. These were the men assigned to Boiler Room No 1.

Boiler Room No. 1 was not used for the entire voyage. Whist in port fire would be raised in No. 1 to power the ship whilst all the other boiler rooms are out cold. Logically, they probably were also "on line" during the first few hours and the last few hours of the voyage too. Not during the main portion of the voyage however.

The men from No. 1 were kept busy doing odd jobs in the engine room. This also meant they were available to replace other fireman or trimmers who just might be taken ill (John Podesta claimed one fireman was taken ill on the day before the disaster) or injured in other boiler rooms.

Paddy Dillon was telling the truth. Much of his other testimony of his experience that night matches very well with what other survivors saw.

 

[Stephen Carey]

Why would you doubt such a thing, Stephen?
Sure, Dillon was just trimmer, but he had been an AB before that. He had done very little time trimming and spent most of it in the main engine room cleaning. This was his first trip below and you can bet he did not want to remain as a Trimmer so would have been watching everything.
I don't know if you have ever been in a triple expansion engine room, Stephen, but I most certainly have... very often.
Dillon would have to have been totally blind not to see when the "big ends" were slowing down...when they stopped and when they turned in the opposite directions during a maneuvering sequence such as he described. You do not need to see the telegraph unless you want to know the value of the order.
Just read your article.
You might like to know that back in the early 50s when I started, you got your head in your hands to play with if you rang down Full Astern from Full ahead without pausing at STOP. The reason given was that the boiler room had to be advised to stop stoking and dampen the fires to temporarily reduce steam production during changeover.

Oops! Re article - meant Charlie, not Stephen. Mia culpa 'nat. Oops! again...what am I doing...must be Scottish heat stroke!

Well Jim, after 18 years at sea as an engineer, that's generally my opinion of the engineroom crew - they did just that, cleaning, and rarely knew anything about the machinery itself - not their job. In fact many of the engineers from shoreside jobs didn't either, until the cadetship scheme came in. The best ones for knowing what was happening and how the machinery worked were Filipinos, but even so they were not trained for it, they were just more interested. In 1912 I find it hard to believe that an unschooled ex AB going to trimmer and then to cleaner would have been any wiser than those I sailed with of any nationality. The Enquiry shows this too, the answers from the firemen and trimmers was often "I wouldn't know that Sir" or "I have no idea Sir" which to me was frustrating to read, because why didn't they just get the Chief and Second engineers from Olympic into the enquiry and ask them the technical stuff?
My 3 double rings astern were all just that - from Full Ahead to Full Astern with no pause in between - not necessary, the bridge wanted to go full astern so that's what they rang - I wouldn't have expected anything else! Only one of the 3 was at Full Away, the others were at standby revs entering or leaving harbour where it was just as alarming but easy enough to do as the engine was already at manoeuvring revs and would go astern with no problems. FAOP not so easy...
Unfortunately I have never been in a steam reciprocating engineroom - much though I would have loved to have been. If I get back to UK Shieldhall is on my itinerary...

 

[Stephen Carey]

Actually, on the Titanic a handful of firemen and trimmers did work in the engine room. These were the men assigned to Boiler Room No 1.

Boiler Room No. 1 was not used for the entire voyage. Whist in port fire would be raised in No. 1 to power the ship whilst all the other boiler rooms are out cold. Logically, they probably were also "on line" during the first few hours and the last few hours of the voyage too. Not during the main portion of the voyage however.

The men from No. 1 were kept busy doing odd jobs in the engine room. This also meant they were available to replace other fireman or trimmers who just might be taken ill (John Podesta claimed one fireman was taken ill on the day before the disaster) or injured in other boiler rooms.

Paddy Dillon was telling the truth. Much of his other testimony of his experience that night matches very well with what other survivors saw.

Maybe so, but that doesn't fit with my experience of 18 years at sea as a marine engineer... In 1912 most men the likes of Dillon et al hadn't even been to school for any length of time over primary education; many would have been semi-literate in fact. Those that had, and were interested in going to sea in the engineroom would have apprenticed themselves to an engine builder or shipyard, as the Titanic's engineers had. I was at sea from 1969 to 1986 and the standard of education of engineroom crews was not spectacular, otherwise they would have gone the engineering route. Even those Junior Engineers who had been in shipyards and engineworks ashore needed quite a few years at sea to learn enough to go up for their tickets - many failed a few times before making it and others just stayed as 3rd engineer (which didn't need a ticket), being happy enough in that rank and salary without the additional responsibilities of 2nd or Chief Engineer. Firemen//Greasers had no interest in doing anything other than their own job - if that at times! If they had, I would have pressed them to better themselves.
The school leaving age for those like Dillon - whose schooling would have been in the 1890s - was 10, later raised to 12 and then 13. I wouldn't expect him to know which way the engines were turning; maybe he did, but I wouldn't bank on it after only a few days on the ship - and the two engines turned in different directions...

 

[Stephen Carey]

There's an earlier thread on this:

How much time between spotting of iceberg and the collision

Modern film and books have suggested it was as long as 30 seconds between Fleet's spotting the iceberg and the actual collision... Im inclined to beleive the collision occoured seconds after the berg was spotted.. I think Murdoch may have seen the berg the same time as Fleet, if not...

www.encyclopedia-titanica.org

Fourth Officer Boxhall testified that he heard three alarm bell rings from the Crow’s Nest and then heard First Officer Murdoch call out orders to Quartermaster Hichens to put the wheel hard over, and the noise of the engine room telegraphs ordering the reversal of the engines.

When live steam to a reciprocating engine (even a big one) is cut off, it stops pretty quickly and then the reversing mechanism is engaged. Take a trip on a Lake Geneva paddle steamer and you'll see how easily and quickly they go from ahead to astern. There's no question of 'crashing gears' or anything like that.

Having written that, at cruising speed in mid ocean, engineers are not normally on the control platform with their hands on all the levers in anticipation of frequent or emergency manoeuvring; so, an engine order being given and put into effect are two different things. Also, the time between any orders given and the Ship striking the Berg was just some thirty seconds, perhaps less, so it's probably reasonable to assume (as opposed to "knowing") that a reversal could barely have been initiated, if at all.

As to your actual question: in all honesty, I really do not know the answer: hope someone else can help and if I 'come across' anything, I'll be sure to let you know.

If you read the article I included in a response, you will see that the engine is difficult to stop owing to windage on the propellers. It's the same for a steam reciprocating engine as for a diesel marine engine based on the same machinery more or less. Shutting the steam off doesn't stop the engine dead at 20+ knots, and putting full steam astern on is likely to damage the engines so would have been carefully done. In my article the astern starting air goes on to slow the engine down before putting the fuel on to go astern, and even then the engine often swings back to ahead again with the cams still set astern and fuel on. At standby revs entering and leaving harbour (which is the reason for standby revs, and the revs that your Geneva boat would have been at all its life) the engine will go astern from full ahead, and will stop almost immediately from full ahead (standby revs) when STOP is rung. Not so at full sea revolutions with the amount of momentum the ship has. The full astern movement on trials has everyone attending the machinery and ready for it - not so at sea...
I'm not convinced that an astern movement was rung on the telegraphs that night - Murdoch would have known that it would not have been effective. In fact I don't really know why he rang STOP!