Below, please find an essay by RapidNadion fan John Bennett containing his thoughts on the Titanic disaster. We offer this post without comment of our own, but encourage you to reply and speculate in comments, as John would like more feedback.
____________
"Did the Titanic have to sink?"
An alternative view.
by John Bennett
At 11.40pm on Sunday 14 April 1912, travelling at over 22 knots, RMS Titanic on
route to New York struck an iceberg. She sank less than 3 hours later with the loss of
more than 1,500 lives, almost two-thirds of the people on board.
It is now the centenary of the event and most have concluded that nothing else could
have been done to save the ship and avoid the large loss of life. There has been much
debate as to whether the ship should have hit the iceberg head-on thus reducing the
number of compartments damaged or whether better use of the ships engines and
rudder would have resulted in a near miss.
For the purpose of this article the Titanic hit the iceberg as history recorded.
My alternative view on the tragedy is that once this had happened and it was known
the vessel was seriously damaged and taking on water, the order should have been
given for full speed astern and astern propulsion should have been maintained for a
long as possible.
I suggest that this course of action may have saved the ship and in any event would
have bought time, allowing the lifeboats to be better organised and passengers to have
spent less time in the freezing water before rescue. The design criteria of the vessel
was that she would remain afloat with four compartment ruptured, the damage
inflicted by the iceberg ruptured 5, however, these compartments did not fill with
water immediately and it is this time whilst water was pouring in which, presented a
window of opportunity in my view, to save the ship or at least prolong her
survivability.
During her sea trials in the Irish Sea the Titanic performed an emergency stop from
20 knots in less than half a mile (ref: The last log of the Titanic By David G. Brown).
At the time of the collision she was doing a little over 22 knots so we can guesstimate
that if the order had been given after the collision that within 10-15 minutes she
would be moving only slowly forward or building up speed going backwards in the
water, time is critical as we know that her propellers were coming visible within 50
minutes as she took on water and all effective propulsion ahead or astern was lost.
However, in my scenario this time would be extended as the vessel slowed and the
intake of water was lessened. Two of her three engines were capable of reverse thrust;
the centre one was forward thrust only. By going astern the more (by now) buoyant
stern end would have the effect of trying to draw the sinking bow out of the water to a
more level angle and reducing the huge inflow of water. By going astern with the
rudder over to starboard would result in the vessel’s stern turning to starboard on a
circuitous course. This would have the effect of increasing the water pressure on the
undamaged side and reducing the pressure on the damaged side further lessening the
ingress of water.
I have searched the Internet and found nothing in support of the above viewpoint, I
am therefore curious for an explanation and apprehensive that the explanation has
been obvious to everyone except me.
John Bennett
I have received some replies which I have listed below so as to save repartition:
by Michael » Thu Apr 05, 2012 4:36 pm
I don't believe the propellers started coming out of the water until about 12:30 am and
weren't fully out until around 2:10 am. The scenario you proposed wouldn't have
delayed the sinking, but might have actually hastened it and it would have made it
impossible to launch any lifeboats. The rate at which the water came in was
connected to the displacement of the ship, not completely, but to a large degree.
Reversing the ship wouldn't have made it any lighter, but it could have increased the
pressure around the hull by the water flowing past and might have increased the rate
at which it entered the ship.
Reply by John Bennett
Thanks for the response and the correction in time as regards the propellers being
exposed, do you know how long the emergency stop had taken in the Irish Sea?
Regarding your view that going in reverse would hasten the sinking of the Titanic, I
disagree, the 6 slits of damage were all on the curved area of the hull. Going forward,
water would be forced in not only by sea pressure but also the forward movement of
the vessel, when stationary sea pressure would ensure the same thing, however, in
reverse the shape of the hull I believe, would increase the Venturi effect and reduce
the comparative pressure in that area.
Regarding the launching of lifeboats, Titanic could come to an emergency stop
quicker than normal as she would only have two of the three propellers working plus
the stern of the vessel is very much less streamlined then the stem. As regards
displacement of the ship, the effect I was trying to describe is that of an object with a
positive angle of attack and given sufficient momentum will rise, perhaps a rather
inappropriate example would be a submarine uses, which it’s sail planes to ascend
and descend. I have been unable to find out what the astern speed of Titanic was but I
would guess between 8 – 12 knots, it’s hull was at an angle as the bow filled but
whether the speed of the vessel going astern could have provided enough lift to
reduce the ingress of water I don’t know.
John
Reply by Sam Halpern » Fri Apr 06, 2012 12:29 am
A moving ship creates a positive pressure field beginning about 1/6 aft of bow and
forward, a negative pressure field between about 1/6 aft of the bow to 1/6 ahead of the
stern, and another positive pressure field from 1/6 ahead of the stern and aft of that.
The actual field itself and the exact neutral points depend on the hull shape.
Unfortunately, the change in pressure due to movement compared to the static
pressure at a depth of 25 ft below the waterline where most of the damage was in any
event would be relatively small, and would not change the inflow-flooding rate by an
amount that could possibly have saved the ship.
Sam
Reply by John Bennett:
Thanks for the comments regarding the pressure zone, which I agree exist in
the area surrounding a normal undamaged vessel under way on an even keel. Your
final comment ‘and would not change the inflow flooding rate by an amount that
could possibly have saved the ship.’ Seems to indicate that you consider that even if
the course of action I had suggested had been taken that the Titanic travelling at some
speed at an abnormal stem to stern angle and going astern would have made little
difference to the outcome either in the sinking of the vessel or the time it took for this
to happen. I am not an expert on any maritime subject but it seems that such a
dramatic alternative action not affecting the time frame (positive or negative) would
be surprising. My original theory revolves around the angle of the hull and the
effective transfer of damage from the starboard front bow and an area beyond to the
aft area, (as the vessel would now be moving in the opposite direction).
We know that on a small-scale objects heavier than water such as water skiers,
windsurfers using sinker boards, swimmers and submarines (depending on ballast) all
use an angle of attack and forward movement all at very low speeds initially to make
a difference to their apparent buoyancy. Though there is a colossal difference in their
size and that of the Titanic, I am not aware that this principal breaks down, plus the
fact that the Titanic was still buoyant. If the Titanic was going astern at sufficient
speed and angle of attack she would not sink. What this speed is and if it were
possible to achieve, I have not got a clue, my premise is that whilst she had astern
propulsion and was higher aft than forward it must have made some difference and I
am still convinced that this action may have extended the time frame and thus have
saved more lives if not the survivability of the ship.
Lady Pattern's book, Good as Gold, reveals that and I quote; “for ten minutes, Titanic
went 'Slow Ahead' through the sea, which added enormously to the pressure of water
flooding through the damaged hull. The instruction lead to the sinking of the Titanic
many hours earlier than she otherwise would have done by forcing it up and over the
watertight bulkheads. 'The nearest ship was four hours away. Had she remained
at "Stop", it’s probable that Titanic would have floated until help arrived."
_______
I don't who's done the analysis but I have included it to show that there are other views
on the sinking.
Surly someone must have replicated the situation using a large model and gone
through all the alternatives. If anyone has any information I would be grateful if they
would pass it on, failing this I will have to try and do it myself just to put some sought
of closure on it for my own curiosity as regarding my reverse theory.
Thanks
John Bennett
____________
"Did the Titanic have to sink?"
An alternative view.
by John Bennett
At 11.40pm on Sunday 14 April 1912, travelling at over 22 knots, RMS Titanic on
route to New York struck an iceberg. She sank less than 3 hours later with the loss of
more than 1,500 lives, almost two-thirds of the people on board.
It is now the centenary of the event and most have concluded that nothing else could
have been done to save the ship and avoid the large loss of life. There has been much
debate as to whether the ship should have hit the iceberg head-on thus reducing the
number of compartments damaged or whether better use of the ships engines and
rudder would have resulted in a near miss.
For the purpose of this article the Titanic hit the iceberg as history recorded.
My alternative view on the tragedy is that once this had happened and it was known
the vessel was seriously damaged and taking on water, the order should have been
given for full speed astern and astern propulsion should have been maintained for a
long as possible.
I suggest that this course of action may have saved the ship and in any event would
have bought time, allowing the lifeboats to be better organised and passengers to have
spent less time in the freezing water before rescue. The design criteria of the vessel
was that she would remain afloat with four compartment ruptured, the damage
inflicted by the iceberg ruptured 5, however, these compartments did not fill with
water immediately and it is this time whilst water was pouring in which, presented a
window of opportunity in my view, to save the ship or at least prolong her
survivability.
During her sea trials in the Irish Sea the Titanic performed an emergency stop from
20 knots in less than half a mile (ref: The last log of the Titanic By David G. Brown).
At the time of the collision she was doing a little over 22 knots so we can guesstimate
that if the order had been given after the collision that within 10-15 minutes she
would be moving only slowly forward or building up speed going backwards in the
water, time is critical as we know that her propellers were coming visible within 50
minutes as she took on water and all effective propulsion ahead or astern was lost.
However, in my scenario this time would be extended as the vessel slowed and the
intake of water was lessened. Two of her three engines were capable of reverse thrust;
the centre one was forward thrust only. By going astern the more (by now) buoyant
stern end would have the effect of trying to draw the sinking bow out of the water to a
more level angle and reducing the huge inflow of water. By going astern with the
rudder over to starboard would result in the vessel’s stern turning to starboard on a
circuitous course. This would have the effect of increasing the water pressure on the
undamaged side and reducing the pressure on the damaged side further lessening the
ingress of water.
I have searched the Internet and found nothing in support of the above viewpoint, I
am therefore curious for an explanation and apprehensive that the explanation has
been obvious to everyone except me.
John Bennett
I have received some replies which I have listed below so as to save repartition:
by Michael » Thu Apr 05, 2012 4:36 pm
I don't believe the propellers started coming out of the water until about 12:30 am and
weren't fully out until around 2:10 am. The scenario you proposed wouldn't have
delayed the sinking, but might have actually hastened it and it would have made it
impossible to launch any lifeboats. The rate at which the water came in was
connected to the displacement of the ship, not completely, but to a large degree.
Reversing the ship wouldn't have made it any lighter, but it could have increased the
pressure around the hull by the water flowing past and might have increased the rate
at which it entered the ship.
Reply by John Bennett
Thanks for the response and the correction in time as regards the propellers being
exposed, do you know how long the emergency stop had taken in the Irish Sea?
Regarding your view that going in reverse would hasten the sinking of the Titanic, I
disagree, the 6 slits of damage were all on the curved area of the hull. Going forward,
water would be forced in not only by sea pressure but also the forward movement of
the vessel, when stationary sea pressure would ensure the same thing, however, in
reverse the shape of the hull I believe, would increase the Venturi effect and reduce
the comparative pressure in that area.
Regarding the launching of lifeboats, Titanic could come to an emergency stop
quicker than normal as she would only have two of the three propellers working plus
the stern of the vessel is very much less streamlined then the stem. As regards
displacement of the ship, the effect I was trying to describe is that of an object with a
positive angle of attack and given sufficient momentum will rise, perhaps a rather
inappropriate example would be a submarine uses, which it’s sail planes to ascend
and descend. I have been unable to find out what the astern speed of Titanic was but I
would guess between 8 – 12 knots, it’s hull was at an angle as the bow filled but
whether the speed of the vessel going astern could have provided enough lift to
reduce the ingress of water I don’t know.
John
Reply by Sam Halpern » Fri Apr 06, 2012 12:29 am
A moving ship creates a positive pressure field beginning about 1/6 aft of bow and
forward, a negative pressure field between about 1/6 aft of the bow to 1/6 ahead of the
stern, and another positive pressure field from 1/6 ahead of the stern and aft of that.
The actual field itself and the exact neutral points depend on the hull shape.
Unfortunately, the change in pressure due to movement compared to the static
pressure at a depth of 25 ft below the waterline where most of the damage was in any
event would be relatively small, and would not change the inflow-flooding rate by an
amount that could possibly have saved the ship.
Sam
Reply by John Bennett:
Thanks for the comments regarding the pressure zone, which I agree exist in
the area surrounding a normal undamaged vessel under way on an even keel. Your
final comment ‘and would not change the inflow flooding rate by an amount that
could possibly have saved the ship.’ Seems to indicate that you consider that even if
the course of action I had suggested had been taken that the Titanic travelling at some
speed at an abnormal stem to stern angle and going astern would have made little
difference to the outcome either in the sinking of the vessel or the time it took for this
to happen. I am not an expert on any maritime subject but it seems that such a
dramatic alternative action not affecting the time frame (positive or negative) would
be surprising. My original theory revolves around the angle of the hull and the
effective transfer of damage from the starboard front bow and an area beyond to the
aft area, (as the vessel would now be moving in the opposite direction).
We know that on a small-scale objects heavier than water such as water skiers,
windsurfers using sinker boards, swimmers and submarines (depending on ballast) all
use an angle of attack and forward movement all at very low speeds initially to make
a difference to their apparent buoyancy. Though there is a colossal difference in their
size and that of the Titanic, I am not aware that this principal breaks down, plus the
fact that the Titanic was still buoyant. If the Titanic was going astern at sufficient
speed and angle of attack she would not sink. What this speed is and if it were
possible to achieve, I have not got a clue, my premise is that whilst she had astern
propulsion and was higher aft than forward it must have made some difference and I
am still convinced that this action may have extended the time frame and thus have
saved more lives if not the survivability of the ship.
Lady Pattern's book, Good as Gold, reveals that and I quote; “for ten minutes, Titanic
went 'Slow Ahead' through the sea, which added enormously to the pressure of water
flooding through the damaged hull. The instruction lead to the sinking of the Titanic
many hours earlier than she otherwise would have done by forcing it up and over the
watertight bulkheads. 'The nearest ship was four hours away. Had she remained
at "Stop", it’s probable that Titanic would have floated until help arrived."
_______
I don't who's done the analysis but I have included it to show that there are other views
on the sinking.
Surly someone must have replicated the situation using a large model and gone
through all the alternatives. If anyone has any information I would be grateful if they
would pass it on, failing this I will have to try and do it myself just to put some sought
of closure on it for my own curiosity as regarding my reverse theory.
Thanks
John Bennett
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