Weight of Titanic
Joe Knapp
Here are some figures from "The Titanic and Lusitania: A Final
Forensic Analysis," Marine Technology, Oct. 1996:
Intact ship, just prior to collision:
(figures in tons)
Steel 21,831
Outfit 11,564
Machinery 8,100
sub-total of above: 41, 045 tons
Margin @3% 1,231
Total, light ship: 41,045 + 1,231 = 42,276 tons
Coal 3,890
Cargo & dunnage 609
Stores 149
Fresh water 592
Reserve feed water 864
Salt water ballast 1,177
Baggage 87
Passengers/crew 113
TOTAL DISPLACEMENT at time of accident: 48,478 tons
*Total displacement at departure: 50,852 tons
Departure draft: 34.0 feet
Joe
Eric Smith
I think it's incredibly interesting that the standard figure of 66,000
tons displacement is shown to be wrong, or at least to be possibly a
theoretical maximum and not Titanic's actual displacement.
"Joe Knapp" <j...@worldnet.att.net> writes:
>Here are some figures from "The Titanic and Lusitania: A Final
>Forensic Analysis," Marine Technology, Oct. 1996:
[ ... ]
> TOTAL DISPLACEMENT at time of accident: 48,478 tons
> *Total displacement at departure: 50,852 tons
> Departure draft: 34.0 feet
The RINA paper, using Edward Wilding's 1912 calculations, has similar
but slightly different figures:
Departure At Collision
Displacement 52,310 tons 48,300 tons
Draft aft 34'4" 33'9"
Draft forward 33'8" 30'9"
mean draft 34'0" 32'3"
It makes sense to me that Titanic would lose 4,000 tons displacement
during the voyage as this would represent about the weight of 2/3 of
her initial load of coal.
-----
Eric Smith | "They were like travellers unwillingly
erics @netcom .com | returned from brilliant realms, not yet
http://www.catsdogs.com | adjusted to their return." - Olivia Manning
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Matt Preston
Right behind you, Eric!
I was going to repost our previous discussion on this. Nowhere can I get
66,000 tons when you look carefully at definitions, tables etc.
Thanks to power of this ng, I reckon this could be a little discovery all
of our own!
Can anybody refute this thread?
Cheers
Matt
Eric Smith <er...@netcom.remove.this.com> wrote in article
<ericsEs...@netcom.com>...
Joe Knapp
Eric Smith wrote in message ...
>I think it's incredibly interesting that the standard figure of 66,000
>tons displacement is shown to be wrong, or at least to be possibly a
>theoretical maximum and not Titanic's actual displacement.
Here is a statement from the May 26, 1911 article in Engineering:
"The gross tonnage is about 45,000 tons; and on a load draught
of 34 ft. 6 in. the displacement tonnage will be about 60,000 tons."
http://www.geocities.com/~ss245/titanic/engr1911.htm
The "Titanic: Final Forensic Analysis" paper gives a departure
displacement of 50,852 tons at a 34.0 mean draft. You quote
similar estimates from RINA of 52,310 tons and 34.0 feet.
So it doesn't really add up, does it? I mean, say they did load
the thing to 60,000 tons. I figure, round numbers, that the
draft will increase by 1 foot for each additional 2000 tons.
So 60,000 tons would give about a 38 foot draft, which
doesn't agree with the Engineering article quoting 34.5 feet
at that tonnage. I don't know which of these papers to trust!
>It makes sense to me that Titanic would lose 4,000 tons displacement
>during the voyage as this would represent about the weight of 2/3 of
>her initial load of coal.
"Titanic: Final Forensic Analysis" gives 1,933 tons of coal consumed.
That seems low; but I went through the numbers and see that it's
believable. The Oct. 21, 1910 Engineering article "The White Star Liner
OLYMPIC" says that the combination of triple-expansion engines and
center turbine improves efficiency by 14 percent, in an experiment
comparing the White Star liners Megantic and Laurentic Those were
identical ships except in the case of machinery, the former having twin
quadruple-expansion engines, and the latter having added the center
turbine. The article continues:
...of greater influence still is the decision of Mr. Bruce Ismay
and Lord Pirrie to fit the new system to the Olympic and
Titanic...
The economy realised by the the system, and its growing
popularity, are the more remarkable when one considers
the great efficiency attained by the quadruple-expansion
engine, especially in the hands of Messrs. Harland and
Wolff. It would be possible to give details from the
performances of their ships on the Atlantic fitted with
quadruple expansion engines showing a coal
consumption in service of 1.4 lb. to 1.45 lb. per
indicated horsepower for all purposes. That this should
be improved upon with the combination system is
particularly noteworthy.
So a 14 percent improvement on that would mean a
coal consumption rate for the Titanic of 1.25 lb/ihp/hour.
Just taking the coal consumed since leaving Queenstown,
that's what, about 85 hours of sailing? If 1,933 tons were
consumed, that's means an average power of 36,000
horses, out of 46,000 possible.
One more anomaly: if you take the departure weight
given in the "Titanic: Final Forensic Analysis" paper
and subtract the amount of coal burned, one gets less
than they quoted for the weight at the time of the crash.
Maybe they took on additional salt-water ballast?
Who knows!
Joe
Andrew and Rebecca Hall
Matt Preston wrote:
> Thanks to power of this ng, I reckon this could be a little
> discovery all of our own!
Just shows to go you, there's always something new to discover.
-----------> AH
Tom Pappas
Edward Wilding's calculations, which were based on either known
measurements or from conditions reproduced by Olympic:
Design Draught 34' 7"
Displacement of Design Draught 52,310 tons
Lightweight 38,760 tons
Deadweight at Design Draught 13,550 tons
Gross Tonnage 46,329 tons
Then he took the average change in draft for three voyages of Olympic at 2'
8" (from departure to arrival) and applied it to Titanic, whose draft at
departure was known to be 34' 0"
Time to arrive 10 am=165 hrs.
1 am Monday to 10 am=57 hours 2/3 of 2' 8" = 1' 9" mean change
32' 3" mean draft
48,300 tons
Assume she would go 3' 0" by stern during voyage,
therefore say 2' 0" by stern Sunday night
if 8" by stern originally therefore 2' 8" by stern say 3' 0"
Mean Draught 32' 3" + 1' 6" = 33' 9" aft
Mean Draught 32' 3" - 1' 6" = 30' 9" forward
It looks a lot like the 66,000 figure could be (mistakenly) derived by
adding the design draft and the deadweight, but I can't think of any reason
to do this. The figures that add correctly are the lightweight and
deadweight to equal the displacement. My interpretation of the above is
that the ship was designed to displace 52,310 tons at nominal loading. The
other possibility that occurs to me is that it could actually be loaded to
66,000 without sinking, but "design draught" suggests that this loading was
never intended.
--
Tom Pappas {:ož
http://home.att.net/~tompappas
"But this script can't sink!"
"She is made of irony, sir. I assure you, she can. And she will."
Eric Smith
If I could return to an old subject for a moment, one that has nothing
to do with the movie :) ...
"Joe Knapp" <j...@worldnet.att.net> writes:
>er...@netcom.remove.this.com wrote:
>>It makes sense to me that Titanic would lose 4,000 tons displacement
>>during the voyage as this would represent about the weight of 2/3 of
>>her initial load of coal.
>"Titanic: Final Forensic Analysis" gives 1,933 tons of coal consumed.
>That seems low; but I went through the numbers and see that it's
>believable.
[...]
>Just taking the coal consumed since leaving Queenstown,
>that's what, about 85 hours of sailing? If 1,933 tons were
>consumed, that's means an average power of 36,000
>horses, out of 46,000 possible.
I really don't know what the practice was - did they load coal for the
round trip before the voyage, or only for one way, and then load again
before the return trip? If it was for the round trip then I can believe
the ~2,000 ton figure. If it was one way, then it should be ~4,000 tons.
One thing that makes me curious is that due to the coal strike in Britain,
they had to scrounge up practically all the coal they could find, including
taking it from other ships whose crossings were cancelled. It seems like
it might have been easier to get reloaded in the U.S.
Tom Pappas
Edward Wilding (again):
His draft computations were based on the assumption that 2/3 of a 165 hour
voyage had been completed at the time of the collision.
Beginning with a design draft of 34' 7" and a design displacement of 52,310
tons, he applied the draft changes observed in 5 voyages of Olympic to
Titanic and concluded that her displacement at the moment of collision was
48,300 tons. That's close enough to 4,000 tons difference for me.
The odd thing about this sequence of calculations, however, is that
Titanic's draft at departure from Southampton - in Wilding's workup - was
34' 0", or 7" less than one would expect for a full load.
Eric Smith wrote in message ...
Eric Smith
"Tom Pappas" <thepapp...@mci2000.com> writes:
>Edward Wilding (again):
>His draft computations were based on the assumption that 2/3 of a 165 hour
>voyage had been completed at the time of the collision.
>Beginning with a design draft of 34' 7" and a design displacement of 52,310
>tons, he applied the draft changes observed in 5 voyages of Olympic to
>Titanic and concluded that her displacement at the moment of collision was
>48,300 tons. That's close enough to 4,000 tons difference for me.
That's what I would think too, but Joe was quoting from this other paper,
"The Titanic and Lusitania: A Final Forensic Analysis," Marine Technology,
Oct. 1996, which gave a figure of 1,933 tons of coal consumed. Since the
Titanic left with close to 6,000 tons of coal on board the only way I could
reconcile that number would be to assume the coal must have been enough
for a round trip voyage. But then I don't see how Wilding arrives at his
change in displacement figure.
Louis Epstein
Tom Pappas (thepapp...@mci2000.com) wrote:
: Edward Wilding (again):
:
: His draft computations were based on the assumption that 2/3 of a 165 hour
: voyage had been completed at the time of the collision.
:
: Beginning with a design draft of 34' 7" and a design displacement of 52,310
: tons, he applied the draft changes observed in 5 voyages of Olympic to
: Titanic and concluded that her displacement at the moment of collision was
: 48,300 tons. That's close enough to 4,000 tons difference for me.
: The odd thing about this sequence of calculations, however, is that
: Titanic's draft at departure from Southampton - in Wilding's workup - was
: 34' 0", or 7" less than one would expect for a full load.
Note that the ship had a capacity of 3547 people,but sailed with 1300
empty berths...those people might have weighed 100 tons,FWIW.
: Eric Smith wrote in message ...
: >If I could return to an old subject for a moment, one that has nothing
: >to do with the movie :) ...
: >
: >"Joe Knapp" <j...@worldnet.att.net> writes:
: >
: >>er...@netcom.remove.this.com wrote:
: >
: >>>It makes sense to me that Titanic would lose 4,000 tons displacement
: >>>during the voyage as this would represent about the weight of 2/3 of
: >>>her initial load of coal.
: >
: >>"Titanic: Final Forensic Analysis" gives 1,933 tons of coal consumed.
: >>That seems low; but I went through the numbers and see that it's
Matt Preston
> : The odd thing about this sequence of calculations, however, is that
> : Titanic's draft at departure from Southampton - in Wilding's workup -
was
> : 34' 0", or 7" less than one would expect for a full load.
>
> Note that the ship had a capacity of 3547 people,but sailed with 1300
> empty berths...those people might have weighed 100 tons,FWIW.
>
This fits in with the definition of DWT we saw previously:
(http://ds.dial.pipex.com/town/square/gl72/andy6.shtml):
"Deadweight (DWT) is the wt in Tons or Tonnes of the cargo, fuel, stores,
water, crew etc, which the vessel is designed to carry in safety".
I would also imagine that the relative salinity at the time must effect
draft. Whilst I am certainly no sailor, I wonder if the Solent experiences
significant changes in the amount of fresh water about.