Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-07-15
7 H E A M M EN- r "A M
Its Inventor Discusses the Criticisms Of
Constructor Nixon.
What It 10 Expected That tho Katahdin
in the Recent warship Disaster.

To the Editor Of The Evening Star:
Your readers of Saturday last were DOUBTLESS
much interested In the letter of Mr.. Nixon, CIV
Ing his reasons for his belief that the Ammen
ram would require speed Of fifty knots per
hour to infict the damage that the Camper
down caused when she sunk the Victoria
through collision.
As it is not expected that the Katahdin will
attain half that speed and therefore less than
one-fourth Of the energy that he supposed
necessary to effect the object, were his
formula and his deductions acceptable, !
would say that we har Q now one ram too
many, when, in fact I look forward for
her trial under steam with great interest
and have the idea that she i'll be found to have
at least one-fourth more speed than any battle
ship aAoat that she will turn the arc of circle
in one-half the time, ind that many experts
will support the idea that with a speed Of ten
knots she would be able to sink any battle ship
she might run into without likelihood Of in
curing serious injury, as did the Camperdown,
or from the guns Of the enemy. Ten knots per
hour gives fraction less than seventeen feet
per second. and this would give a striking force
of 9,S68, 500 foot pounds by the formula ordi-
narily accepted by scientists. I suppose her
possible speed will be found twenty knots, Civ
ing four times the energy above named. which
would seem quite enough to overcome any in
battle ship.
AN IMPLIED DIsCoURTEsY.
The expression Of Mr.. Nixon that had
lation to the speed required for the Katahdin
seems the expression Of an implied discourtesy
on the part Of any one who asks explanations
Or who expresses dissent from what he had given
to the public in relation to the Kstahdin.
His idea that momentum" pure and simple,
does the work In collision is not the formula
accepted by any scientist known to me. Lot
us consider projectile of 1000 pounds moving
at the rate Of 1000 feet per second. This, with
Mr.. Nixon, would imply 62,110 foot pounds
momentum, If considered in relation to rams,
but the ordnance officer would add that the ac-
cepted and undisputed formula for projectile
having those factors, and the momentum"
above given, would give striking force Of Ga
110. 900 foot pounds.
Within the past three months Great Britain
has given the world two object lessons Of great
significance in naval warfare. The first and
most important was in torpedo boat IS run
ming into the battle ship Nile and filling her for
ward compartment with water. I call to the
consideration Of Mr.. Nixon that the torpedo boat
is put down as having thirty-eight tons dis
placement. If we assume her speed at twenty
five knots we find the momentum is twenty
nine and fve-tenth knot tons, yet If we look at
1t in the light Of the accepted formula we find
that insignificant momentum.in its factors rep
resents a striking force OF 81 knot tons. We
see the extraordinary fact that SO frail a con-
struction and so light weight did with a high
velocity endanger . battle ship through COLI
sion, and so far as is known, without being
sunk by the blow she gave.
ANOTHER OBJECT LESSON.
The other object lesson is in the collision Of
the Camperdown with the Victoria. The
Wanted ram bows" were found so weak later
ally that they were knocked out of place and
bent around. The involuntary act of ram
ming endangered the safety OF the Camper
down to such degree that the question Of
whether she could be kept afoat was one Of
great gravity. In short II these so-called
Trans" with their supposed mighty "ram
bows" ram large vessel, they do SO with ex-
treme peril to themselves.
Should any naval constructor design "ram
bows" that would offer q reasonable immunity
from destruction Of the vessel running into the
side of avessel moving with same rapidity,
he would relieve many captain who may
now regard 'ram bows" as now more orna-
mental than useful in naval warfare.
Whatever idea is expressed by any one whose
opinion should have weight is proper and
often profitable subject for criticism pro or
con. / shall feel much obliged to Mr. Nixon
and other able naval constructors should they
discuss the points OF the Katahdin whether in
comparison with vessels having ram bows. or
abstractly, as to capability of doing the work
for which she was designed. Indeed it is my
purpose to do SO myself at a proper time andin
a proper mood. When her plans we're COM
pleted and laid before the advisory board by
the bureau of construction some two and a
half years ago I was invited to inspect them,
and asked if 1 thought that they fairly repre-
sented the accommodation made by the ad-
visory board OF 1881 for the construction Of
five rams on my design. replied that in my
belief the plans fairly developed the design
and specifications laid before that board. At a
later period it came to my knowledge Incl
dentally that the bow and some other parts of
the construction had been materially changed,
in my belief to the detriment of the full effec-
tiveness Of the vessel as originally designed,
but do not insist that my opinion should be
supreme in considering the points of the
marine ram, in which had the intelligent aid
Of several navy officers, and especially Of John
Lenthall, after his retirement, who was for
many years our chief naval constructor, and OF
those have known the ablest.
DAN'L AMMEN.
AMMENDALE. Nd, July IA, 1898.