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RETURN To an Order of the House for a copy of the report of Messrs. Keefer & Smith, C. E.'s, regarding… British Columbia. Legislative Assembly 1894

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 57 Vict.
Re Proposed Bridge at Kamloops.
To an Order of the House for a copy of the report of Messrs. Keefer & Smith, C. E.'s,
regarding the proposed bridge at Kamloops.
Chief Commissioner of Lands and Works.
Lands and Works Department,
20th March, 1894.
Pboposed Highway Bridge Across the Thompson Biver Below Kamloops, B. C.
Chambers 44 and 45, Five Sisters' Block,
Victoria, B. C, March 14th, 1894.
To the Honourable Forbes Vernon,
Chief Commissioner of Lands and Works :
Sir,—We beg leave to inform you that, in accordance with your instructions conveyed to
us on the 10th ult., we have examined and surveyed the Thompson Biver below Kamloops, for
the purpose of obtaining the necessary data for designing and estimating the cost of a timber
highway bridge across that river.    We now have the honour to report as follows:—
The Site.
An examination of the river from Kamloops westward showed that a contraction in its
width took place immediately below the old Post of the H. B. Co. An accurate traverse of the
bed of the river in this vicinity showed that the shortest distance from bank to bank is at a
point 267 feet west of this Post. As the soil of the banks, the velocity of the current, and
the nature of the river bed are to all appearance unvarying throughout the whole length of the
traverse, the shortest crossing is, therefore, the most suitable for bridge construction.
At this point the total distance from bank to bank is 860 feet, from high water mark to
high water mark 903 feet, and from low water mark to low water mark 703 feet.
Owing to the river being frozen at the time of our examination, we were unable to gauge
the velocity of flow, but common report gives the low water velocity at two miles per hour, and
the high water velocity at four miles per hour.
At extreme low water the greatest depth of the river is at a point 500 feet from the south
bank. This depth is 18-|- feet. The difference between the extreme flood level of 1882 and
extreme low water is 22 ^ feet. The south bank is a sand flat, untimbered excepting a
narrow fringe of small cottonwoods on the river slope.    The north bank is similar.
The bed of the river is of soft yielding material. Borings were taken at frequent intervals by means of a drill attached to an iron gas pipe, fifty feet in total length. The following
are the results: —
Distance from
south shore.
75 feet
175 „
375 .i
400 ,,
525 „
625 ,,
725 „
Depth of
i 8-10 ft.
14 9-10 ft.
13 8-10 ft.
11 9-10 ft.
17 5-10 ft .
10 6-10 ft .
3 3-10 ft.
First stratum.
2 ft. gravel	
11 ft. hard gravel.
3 ft. hard gravel..
ft. soft sand 	
19^ ft. soft material
3£ ft. gravel	
8 1-10 ft. sand ....
Second stratum.
18 7-10 ft. soft material.
1 ft. soft material..
1 ft. hard material.
3 ft. gravel	
4 ft. sand	
22 ft. sand & gravel
Third stratum.
11 ft. clay, sand,
and gravel.
3^ ft. hard gravel .
1 8-10 ft. hard material.
20 ft. very soft material.
1\ ft. stiff material
1 3-10 ft. gravel...
2 ft. gravel	
Fourth stratum.
1 ft. gravel	
3 ft. hard marl	
\ ft. very hard material.
3 ft. sand	
20 ft. stiff material
3 6-10 ft. stiff material.
25 8-10 ft.
32 6-10 ft.
20 1-10 ft .
43 9-10 ft.
42 5-10 ft.
39 4-10 ft.
39 ft	
Drill stiff.
Drill stopped.
Drill easy.
These borings indicate that long pile foundations will be required, 1188 Re Proposed Bridge at Kamloops. 1894
The Proposed Structure.
Owing to the facility with which wooden Howe Truss Spans can be framed, and their
economy as compared with other structures, we are of the opinion that the Howe Truss is the
most suitable for the proposed bridge. We propose a trestle approach on the south bank 30
feet long; from the trestle approach, one span of 150 feet clear opening; from this span a
draw of 180 feet with clear openings of 76 feet; from the draw three spans of 150 feet clear
opening, and from the end of these spans a trestle approach on the north bank of 105 feet
length. Each span to be 16 feet wide between the bottom chords, and 22 feet in depth, the
bottom of the lower chords being not less than 10 feet above flood level. A span of not less
than 150 feet clear opening is necessary to admit of the free passage of drift timber during
floods and sheet ice during winter. A iess span would involve constant danger to the stability
of the piers.
The piers proposed are framed structures of three bents, sheathed on the outside with
three-inch planking. These rest on a substructure of piles protected by a stone filled crib-work
casing which, in its turn, rests on a brush mattrass. Each pier has attached to it a substantial
ice-breaker, triangular in section and projecting 47| feet out from the centre of the pier. The
extreme end of the ice-breaker is protected by clump piles and its upper surface by railroad
iron or other suitable material.
The exact position of the draw has not been definitely located. It will be necessary to
observe the river during floods in order to ascertain the course of drift timber. The draw must
be placed where drift timber is least.
The total length of the proposed structure, exclusive of approaches, is 804 feet, and inclusive of approaches. 939 feet. During low water the piers will occupy an area of 1,122 square
feet in the sectional area of the river, and during high water 2,752 square feet.
The sectional area of the river at low water is 7,983 square feet, and at high water
25,915 square feet. The piers will, therefore, contract the present channel during low water
14 per cent., and during high water 10J per cent.
The Estimate.
Our estimate of the cost of the proposed structure, based on quantities compiled from an
actual design, is as follows:—
Approaches I	
Land piers	
River piers	
Pivot pier and draw protection	
Add for engineering and contingencies, 10 per cent	
Total Estimate   $44,802 16
Documents Submitted.
We submit for your consideration the following documents:—
1st.  A plan on scale 100 feet to one inch, showing the proposed location of the bridge site.
2nd. A general plan on a scale of 20 feet to one inch, showing the plan and elevation of
the proposed structure.
3rd. A detailed estimate showing quantities and prices.
Trusting that we have fully executed your instructions and that the results will meet with
your approval, We have the honour to be,
Your obedient servants,
(Signed) Keefer & Smith,
Civil Engineers.
Printed byRiOHARD Wolfenden, Printer to the Queen's Most Excellent Majesty,


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