The evening times. [volume] (Washington, D.C.) 1895-1902, 1901-09-25
A GIANT AMONG WHEELS.
Largest of Its Kind Being Finished
In MnrNIRnh.

. ia VIII AtAAh
BALTIMORE. Sept. 25.-The Robert
/ Poole * Son Company at Woodberry. is
about finishing the largest wheel of its
kind in The world. The wheel is sixty-five
/ feet in diameter, and. with its supports.
/ Will weigh over 1o11e5 pounds. II was
/ ordered by the Calumet and HecIa Mining
/ Company 10 carry away the refuse from
! the stamp mills at one OF the great mines
i on Lake Superior.
( 1t is known as sand wheel Upon the
! inner surface Of its rim will be arranged
/ $50 buckets. each measuring I feet 6 inch
I Is 10y 8 feet. As the wheel reyolvcs each
/ bucket viii scoop up it's capacity OF earth
. and refuse. which it viii dump into
I trough at the top Of the wheel, whence
I il VIII De carried away by the water in
/ a sluiceway
When the Calumet and HeCIa Company
! decided to order this wheel it found that
. the Baltimore plant was the only one pre-
/ pared to build the giant entirely under
4 cover. one Of the first requisites for
. building such a wheel was a pit in which
/ part of the wheel might be sunk as 1t was
/ put together. and it was found that the
Baltimore company had one exactly suit
/ ed 10 the purpose. the pit being 100 feet
[ long. = feet wide and 20 feet deep. while
the building over the pit is SO high that
{ IL easily accommodates the huge structure.
/ The order Tor the wheel was given in
June. 1909. and work was at once begun
on the various parts according TO the
plans drawn by Z. D. Leavitt, an engi-
neer of Cambridgeport, Mass.
one Of the first considerations in max
ing the wheel was the strength and safe
~ Of the axle. and that was ordered from
I ba l. r1rrt-t f,1rr7 T~arrCry- ThFc
shaft is BY itself an enormous affair Il
is twenty-seven feet long. thirty-two
inches I'm diameter, with a twenty six-inch
hole through the centre and weighs ~
Z CJO pounds. All Of the finishing work on
it was done in Baltimore.
Because Of the enormous size Of the
wheel It had TO be built in sections, and
II was laid of in twenty segments. II
consists Of two concentric rims. one on
the inside for the purpose Of strengthen
ing the entire structure. and another out
side, consisting Of a toothed rim fastened
to the inside rim with bolts.
Each segment had 20 be finished in
practically the same temperature. for
had two Of them been planned In differ
ent temperatures they would not have
ntted because Of the expansion ana con-
traction of the metal. Great interest was
taken IN the work by the mechanics con
nCctcd with the plant, and when the seq
ments were completed there was much
speculation as 70 whether each part would
mt perfectly.
The putting together Of the wheel in
the shop required several weeks. When II
was completed II was found that the parts
fitted with really wonderful accuracy re-
hectiug great credit upon those in charge
Of the work investigation showed that
a line run through the joint Of two seq
ments on one side and continued through
the centre Of the joint Of the two seq
ments on the opposite side was less than
one One-thOusandth Of an inch out Of true
or as near as human skill could come 10
making il absolutely perfect. the differ
enCe being so slight chat II would hardly
be detected by the most powerful instru-
ments- The outer rim was as perfect as
the inner. ana so evenly are all the seq
mentS laid together that they seem to
constitute one piece.
Running from the hubs on the ends OF
the shafts 70 the segments are forty steel
arms. built on the principle Of a bicycle
wheel. and arranged with special nuts and
threads for fine adjustments when the
wheel IL finally set w IN the mine. In or
der 10 I'll the contract several pieces Of
special machinery had TO be built TO com
plete the various parts. One Of the most
Interesting is that employed 10 cut down
the teeth Of the big outside rim until they
correspond exactly with the teeth Of the
smaller wheel. 1y which the motive power
Is TO be communicated.
Those who have seen an ordinary set OF
cog wheels are not apt 70 think that the
cutting OF the teeth to tit would be diff
Gull DuL VIII "A cog Wlee4 - sctt III
ameteT the proposition IS quite different
So carefully is the work being done on
this big wheel that a ma gnifyfng glass Of
great power Is used 10 see whether or not
the portions taken of by the machine
correspond 70 marks which have been
placed upon the rim after careful and in
vOlged calculation. This is beng done
while the wheel IS being set up. 50 won
derfUEy true Is the adjustment OF the big
wheel that Fl IS easily turned by man
operating small screw.
When put into actual use the wheel will
be operated BY an electric motor Of about
400 horsepower. It's motive power viii
be communicated 20 TIE big wheel from
smaller cogged wheel Upon each seq
meut Of the big one are IS teeth or "A
total Of 52n. The smaller wheel by which
10 VIII be driven is three feet In diameter.
When working AT the mines il is expect
cd that the big whe=- viii make ~ rev0-
luuous minute. which viii necessitate
The smaller one going at the rate Of a bout
20 revolutions per minute.
It is expected that the wheel will be
ready for delivery in about four months
and when IL is. between 30 and 40 gou-
dnla cars VIII be required for its trans
pDTtation. several Of which viii have 10
be built especially for the accommodation
OF the huge castings