Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1891-07-25

should have 10 feet of water: but the locks
should be ea0x22 feet, instead of lsx220 With
! 10 feet of water and locks 22X22O steel Darges
/ may be used CARRYING anywhere from 600 to
/ $40 net tonS:according to model OF OtISe- Ihe
! lines of such barEes should be made TO con
! form to n standard This IN view OF tne
] fact that with the lO-foot navigation ana the
1 steel large plant power-tOwinE (Dy drlVen
| caDle) would be used, and the progress or
! the boats would be uniform, whatever tne
model wherefore the authority administer
! ing the towing plant should eStaDilsn u GER
! tain limit of fullness of lines in the poats.
! Builders might make their lines as mucn
| finer than the limit as they might see Mt to
| make them.
Three Miles an Hour Might Be Made.
The standard" lines should give about
700 tons carrying capacity, with Il good bow
| and rum in the model. With proper tow
ing plant a progress of three miles an hour
might be effected (see treatise on driven
cable towing, herewith sent you). Move
ment of canal boats by propulsion Is rad
ical mistake.
While speaking of the proposition afore-
said for making ship canal on, or generally
along the route of the Erie from Buffalo to
Albany, 1 note that the advocates of that
scheme appear to be ignorant of the fact
there are 600 bridges across the Erie Canal
between the points named. The average dis
tance between bridges, is accordingly some
thing less than 8 100 feet Not only is the
abolition or material reduction in number of
these bridges impracticable, but the appro-
priation of space necessary to making big
ship canal on the Erie route, is not to be
seriously represented as practicable As
you have said: 1.-The expenditure" would be
Impossible"
Noticing the proposition to make the locks
of the Niagara Canal 400xS0 feet in the cham
Der, am led to remark that whlle this size Is
greater than is necessary for passage OF any
lake vessel now in existence or presumably
to be built, the width is not sufficient for
passage, at one operation, OF two OF the
larger lake vessels: MANY of these have beam
not less than - feet, and there are several
examples of a beam of AZ feet. The Il. Z.
Pope is 3S7N42. The Aurora is 29OX4l. The
Caledonia is 2172N42. And even were the
locks s6 feet wide You could not pass two
vessels of AZ feet beam except you were to
Il Il your lock very slowly.
Even were the traffic, for accommodation
of which the canal is to be constructed
promises to be sometimes, that is to say at
certain seasons, great enough to demand
extraordinary provisions for securing dls-
patch in locking the lock OF size sufficient to
pass two vessels abreast does not recon-
mend itself. If circumstances affecting con-
strnction are not opposed to such plan lock
Of double length might be adopted, having
gates midway of its length. Then either
half might be operated independently as
single lock.
Locks Could Be Passed in Twenty Minutes,
Suppose the largest vessel to be locked is
340N42. She demands lock 340X4S, in the
clear. With lift of no more than Is feet,
with ample supply of water the vessel may
be passed up through such lock in 20 min
utes Four minutes to steam in; two min
utes to make fast; eight minutes to fill; two
minutes to cast off; one minute to open
gates, and three minutes to steam out-20
minutes. Add five minutes for delays and
say lockage occupies % minutes. Then you
may, traffic being equal each way, pass
sold lnuTS
some Is minutes to spare; and by providing
a second lock, of same size, la vessels may
be passed in "a hours.
If YOU undertake to pass two vessels in a
lOckage, expenditure Of time per lockage
will be (4-2)-(6-2) 2)-lO-l-(24)-(2-3) or 35 min
utes; add five minutes delay and you have
4l minutes. Say lockage occupies 10 min
utes. Then YOU may make 3j lockages in a
hours, passing y vessels; and had you room
to pass three at time you would not handle
more than los. We make no question of
economy of water in this case, because you
are supposed to have enough, and to spare.
Suppose the big lock at the 800" (s00Nl0G
feet5 may be operated in average time of
53I5 minutes, (l31S minutes greater time than
now required), passing four vessels at lock-
age; then vessels locked in "a hours-10S.
With two locks, 35Ox5O feet, or thereabout
making 81 lockages each. passing a single
vessel each time. passages would be ia.
If the vessels could come regularly, (each
day the number making the average per
day of the seaSOn) one lock 5JONJO feet could
handle, in a season of 220 days, vessels in
number sufficient to carry, at average cargo
of 600 tons (for each passage through canaD
about twice the present freight tonnage OF
Ste. Marie Canal-but they come in fleets
sometimes and consequently the canal Is
sometimes crowded"
Provision for Traffic VIII Be Made.
Ample provision for traffic as great as /,
the canal will at any season be called upon |
to handle is, of course, properly to be made |
in planning ship canal; and in this con- /
nection any reasonably certain increase of |
traffic should be duly taken into account. |
But construction of the work with view to |
future enlargement seems more judicious |
course than one in which very large ex- /
penditures would be made in anticipation of |
business that finally may never ma |
teraliZe:n that may never grow according to |
ton: or that, actually growing as eN- |
pected to, may be diverted to some route |
not vet projected.
The Nicaragua people, l am told, purpose |
making their locks large enough to pass two |
large ships at once. Should the Nicaragua |
Canal handle Il tonnage twice as great as !
that which, according to Mr.. Nimmo's est- !
mate of 1850, would have sought the Panama |
Canal, it will need to pass lin ships averag |
ing l 500 tons cargo) about three vessels each |
way daily. II the vessels seeking that canal /
are in number twice as many as would have,
according to Mr.. Nimmo sought the Panama
Canal the Nicaragua Canal will have topass |
about four vessels each way daily. Their
locks should be large enough to pass big I
man-of-war; 1--WE may take the chance that |
this provision may benefit some other nation |
more than it will help us); but from a |
merely commercial standpoint the provision |
OF double locks seems uncalled for
In 1885 the passages through the SueZ canal |
were greater in number than ever before, or |
since The vessels averaged !, 80 tons |
(measurement). The passages averaged not