TM 5-818-5/AFM 88-5, Chap 6/NAVFAC P-418
convey the loads over a 4-year period of operation. A
wrapped and welded on 0.177-inch round rod. The well
large stream of oil shall be pumped to the gears and
screen shall be furnished in lengths of 10 or 20 feet.
bearings by a pump located in the base of the housing.
One section of screen for each well will be provided
The vertical shaft shall be hollow to allow for easy ad-
with a stainless steel bottom plate.
justment of the pump shaft. Provision shall be made
(j) Filter sand. The filter around the well screen
for circulating water through a copper coil installed in-
and riser pipe shall be an approved washed (clean) sand
side the case. A flexible drive shaft, Watson-Spicer
or crushed stone composed of hard, durable, uniformly
WL-48, or equal, shall be provided with each gear
graded particles free from any inherent coating. The
drive. The shaft shall be a minimum of 36 inches long
filter sand shall contain no detrimental quantities of
and provided with drive flanges to fit the engine and
vegetable matter, nor soft friable, thin, or elongated
gear drive. A protective cover made of galvanized
particles, and shall meet the following gradation re-
sheet metal or expanded metal shall be permanently
quirements:
attached between the engine and gear drive to shield
Filter Sand A
the drive shaft.
U.S. Standard
Percent by weight
(e) Standby equipment. At the commencement
Sieve No.
passing
of pumping, the Contractor shall provide and have in
1/4
100
4
95-100
stock at the jobsite three new complete standby tur-
6
85-100
bine pumps. During the pumping period, the Contrac-
10
55-85
tor shall continue to have a minimum of three (new of
14
28-65
rebuilt) pumps available as standby units, which shall
16
20-55
be complete with column, shafting, pump head, gear
20
10-32
30
0-18
drive, and flexible coupling.
40
0-10
(f) A minimum of 20 feet of each size of header
If blending of two or more sands is required to obtain
pipe and two of each size of Dresser couplings (or
equivalent) shall be on site for emergency repair if nec-
plished so as to achieve a uniform mix approved by the
essary. Twelve S-inch flanged nipples shall also be kept
C.O.R.
on site for adding S-inch rubber or plastic cloth dis-
(k) Discharge system. The discharge piping is
charge hose for emergency pumping of the deep wells
for the purpose of conveying the water from the dewa-
in event of discharge pipe failure. Sixty-five hundred
tering wells to the flotation channel on the south side
feet of S-inch rubber or plastic cloth hose shall be kept
of the cofferdam area. Under no conditions shall the
on site for pumping of individual wells.
Contractor discharge water from the dewatering sys-
(g) Operation and repair or replacement. The
tems outside of the cofferdam dike other than at the
pumps shall be operated so that the water level in the
specified location. The header pipe installed at the
wells is not lowered below the pump bowl. The pumps
specified locations shall be standard structural grade
and engines shall remain in operable condition at all
pipe with the following minimum wall thicknesses:
times with no more than two wells or pumps being in-
operative at any one time. No two adjacent wells or
Pipe diameter, inches
Minimum wall thickness, inches
12
0.22
pumps shall be inoperative at the same time. The Con-
18
0.25
tractor shall take immediate steps to repair or replace
24
0.25
any well, pump, gear drive, or engine which is inopera-
30
0.25
tive. Should the efficiency of a dewatering well show
36
0.28
any significant reduction from its initial efficiency,
42
0.28
the Contractor may, at the direction of the C.O.R., be
The diameter of the pipe will vary from 12 to 42
required to redevelop and/or chemically treat the well
inches. Connections may be made either by welding or
as directed by the Contracting Officer, the cost of
by Dresser couplings with tie rods. The pipe shall be
which will be paid for under paragraph 3 (Changes) of
laid straight, on approved blocking, in a workmanlike
the General Provisions of the Contract.
manner. Where crossing a road or ramp, the pipe shall
(h) Riser pipe. The riser pipe for the wells shall
be laid in an open separate culvert. The discharge pipe
be 16-inch diameter, 0.250-inch or thicker wall, steel
through the cofferdam dike shall have welded joints
pipe.
and be provided with "seepage" fins. A 42-inch Calco,
(i) Well screen. The well screen shall be John-
or equivalent, flap gate shall be installed on the end of
son, Houston, or equal, wire-wrap type 304 stainless
each discharge pipe. The discharge line from the well
steel screen with a minimum inner diameter of 15
to the header shall be 8 inches in diameter and include
inches (16-inch pipe size) with a nominal length of 100
a gate valve that can be locked or will remain in a fixed
feet. The width of the slots will be 0.040 inch. The
position while partially closed, a positive check valve
(keystone or trapezoidally shaped) screen wire shall be
and a pitometer cock for insertion of a pitot tube to
G-16
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