, 1866-01-09
MIR. DAYS SHIP CANAL PROJECT.
ObteclIons Preseated by Col. Cram OF
tho United States Engineer Corpa.

tho United States Engineer Corps.
The Detroit Advettssr publishes the follow
Ine letter from Col. Cram Of the United States
Engineer Corps, to Mr.. Horace 4. Day, in re-
laliou to his Niagara Ship Canal project:
DETROIT, I'm ) 1864,
SIR: The drawing Or ~ Inclined p'aue you. At
rcseuted to rae for ny opinion Of ita metit5, ard
which IL proposed to supcEsede the construction az
Lin locks altogether fot ship eanal On the Amen,
my attention, although, nom want of ting, to
Nmliea degree; and Ii must be understood that
much more time Of the engineer should be de7oted
to bestoW, before decided opinion Of Its Iue ner
i1s In Ill fts eseeuthl parts can be formed IN se-
spect to is practical operations On 20 lasgc aseae
two and half miles, and the difference OF ele-
Yation Of its Two extremitles three hundred
and twenty tcet, giving an inclination Of one
hundred aud tWeuty-eight feet to the mile.
which Is q triae less than TWO and i half fee.
vertical rise In ascending to one hundred feet
horizontal, making the angle Of elevation Of
Is one degree twenty three minutes.
The case In question, therefore, may be said
to come within the limits Of the use Of inclined
planes rs Substitute for lift locks on canals.
And the case ia favorable In that the total
lockage In the proposed canal eau ha brought
by one Inclined plane Of uniform grade This
ability to coudensc IN this proposed canal, il
also favorable for tho construction ofa scriea Of
locks. The site for the proposed plane Is
favorable in regard to the cost Of eonstruc~
on y t1e 70 tne a
ducing the very best possible foundation ,,of
rocks] for the plane-a feature of vast i--uror~
| tance for such q work. For the )-,cks. too.
] the rock foundations would be- nIiehly fayor-
able. The great Saving Of the foF passiue. 8
vessel ADORE what would be consumed bJ .
men to be continually employed in The labor
\ Of passing the v-sse!s, are the probable I'D
! vantages offu.portance In favor Of the Plane
The problem Of engineering for its con-
| strnction Is very simple, and there Is no
\ question as to the feasibility Of the construc.
tion. ne original cost and subsequent re-
pdns ahd !abo- to carry on the operations OF
pass'ng, vessels would probably be IN iayor Of
t!11e plane.
/ But the practical problem OF the working
= upon the plane, after It's construction, Is what
tie engineer should carefully look into before
embarking 10 the construction. To this can
only briefly allude at this time.
The total weight to borne by the p1ars al
the movable basin Of water Containing tho
ship with Its cargo would lot probably Exceed
5000 tons for the hesiyiest draft (Il1< feet, to
| which the eanAl should be adapted, The force
OF traction to more this up the plane upon
its rollers would be. ythers ,ztTe no friction,
1,2o1 tons only. The pressure at right angles
be nearly 4,co tons. NOV this produces ffic-
tion, the precise amount OF which can be cal
| culnted, but for the want Of time t. obtain il,
1T will not be stated here. The rollers, j. their
journals are not too large, will greatly dimns-
! ish the friction, but the friction, whatever 1t
may be, must be added to the 1,2o7 tons
I SyS x,x1A ~ 1%n{1 4Hs$ ~
| IN order to move the basin, with its ship, up
[ the plane. The pressure Of the pulling chain
| or wire cable also canses friction; the power
| to move the cable and overcome its Fiction
also augmeuts the force Of the traction The
strain upon the cable, to overcome ali this
ant practical features to bo investigated, In
! my estimation, In the whole invention. Should
| the cable break for want Of inherent strength.
the plunge of the movable basin, with It. ship,
| into the 1oEet well-receiviug dock, would 6e
disastrous in the extreme. On the contrary,
| complicated, BY multiplying the number to
attain strength: thah The practical d1lhealty Of
Interested consequent force Of friction,
! and Of working them, would be Objectionable.
| Again, In the using Of the cable Or cablez for
| so great length Of two and one-haf miles,
when necessarily laid 80 ne1r horizontal as
In m angle Of one degree aud twenty J-three
arIan curve,' whcn nc attempt to draw
heavy load at the end Of the ch2in, will come
into operation here. Provision must be made
for this in the Invention, Or very serious prac-
tica1 difficulty will be realized when the plane
is put n operation for passing the ship. This
| opposition to the catenary is dependent upon
t6esize, length and inclination TO be given to
| the cable, and can be accurately COM
puted, as also the friction. The
strength Of the cable, effect OF the
| catcnayy, effect Of friction and mode ot
! working tho cable SO as to redace these op4
| Posing - 1aes to the minimum, a1e the only
| Vs1e-lous Of practical difficulty Of anT mo-
:er r. to ID osSss1cr.is h!ore e: II
merits Sr possible de11aaurits Of tie il yentioa.
hold my opinion in reserve upon these i'm
poEtant points. Nor would express anJ
until sufficient time and means arc at my com-
mAud to determine their actual measures,
which can be most satisfactorily done before
constructing the plane by one competent to
the task. But by Withholding my opinion on
. these points. do not wish to be understood
a. expressing an opinion that they cannot be
fully provided for In the invention. am,
very respectfully. Jours, IT,. CRAM, :,
II Colonel U. 8. Corps Engineers.