Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-10-31
ARCH IS MADE SAFE
Washington Aqueduct Secure
Against Future Leakage.
METAL TUBE Sol FEET LONG
This and Other Improvements Pre-
vent Further Loss in District
Water Supply.

The safety of the long masonry arch
over the valley Of Cabin John run. sew.
eral miles west of Georgetown, is assured
for many years to come. The arch was
built by Gen Meigs in the late fifties to
carry the Washington aqueduct across
that wide valley. The original conduit
over the bridge consisted of sectional
brick tunnel having q diameter of about
nine feet 1t served its purpose well for
about half century Of constant use, but
finally. about a year ago. developed such
extensive leaks that the water supply of
the city of Washington was appreciably
diminished and the stability of the big
stone bridge was seriously menaced.
At the instance of the army engineers
in charge of the aqueduct system. Con-
gress at its last session appropriated
$4,000 for the repair of that section of
the conduit located within the bridge
structure. At that time it was estimat-
ed the leakage in the conduit at that
point averaged about 100000 gallons of
water a day. AS result of operations
conducted during the past summer the
defects in the conduit have been remedied
and the leakage stopped completely.
Water-Tight Tube Installed.
That improved condition followed the
installation Of a water-tight cast iron
tube entirely across the bridge. This
tube is sol feet long and about eight
feet in diameter. 1t is built in six Sec
tions. containing 167 rings. Each ring
is composed Of six segments three feet
in length This metal tube extends
beyond the abutments at both ends of
the bridge. where it joins the conduit
;u;~ 4
The iron rings were placed inside the old
brick tunnel. They will be lined on the
inner side with concrete and the outer
space between the tube and the brick
tunnel will be filled with grout composed
Of sand, cement and water.
All the iron work has been practically
completed and the only things remaining
tube and place the grouting. Capt. Han
mum, assistant to Col. Langfitt, the en-
gineer officer in charge of the District
water supply system. who is in charge
Bridge, says that the work will be ell
tirely completed before the 1st of Deem
Der.
Its prosecution has been attended with
considerable difficulty in order not to in
terfere with the regular water supply of
the city or'the constant travel over the
bridge. This situation vas met by filling
the reservoirs each week and emptying
the conduit for two days at time and
then filing the reservoirs and emptying
the conduit again. That system per-
mitted but two days continuous work in
every seven at the bridge. but was alb
solutely necessary to preserve an I'M
broken supply of water.
Plan Entirely Successful.
That program has been followed ever
since the beginning of the work. in June
last without causing single comp amt
of shortage in the water supply or of
delayed traffic at the bridge. but it natur-
ally prevented rapid work on the tunnel.
During the same period repairs have been
made to about /, 100 feet Of that section
Of the conduit built through solid rock
about half a mile this side of the intake
just above Great Falls. The new lining
at that point is composed of concrete
aid on steel 4orms. All the repairs to the
old conduit will be made within the limit
of cost fixed by Congress. They include
the replacement of the old waste weir
near Great Falls with a more substantial
sluice gate