74
APPENDIX P.
REPORT OF TESTING COMMITTEE.
Geo. S. Mokison, Esq.
Chief Engineer K. C. & M. By. & Bridge Co.
Dear Sir : The committee appointed to report on the results of the testingof the Memphis Bridge on the 12th of May, 181)2, submits the accompanyingtabulated statement of deflections observed in the different spans of the bridge, 1under the several test loads applied :
The sign— indicates a downward deflection. ,'... . , .. .>t '
The sign -j- indicates an upward deflection. . , ci , '
The statement gives the deflections for the north and south trusses of eachspan, and also movements eastward and westward of the north and south rollerbearings on'Pier II, the other beai’ings being all fixed. o. ! -
The testing was done with 18 locomotives weighing in the aggregate 1405.7tons.
Load I was applied to the cantilever arm east of Pier I. It consisted offour locomotives covering the entire length of cantilever and weighing 842 tons.
Load II was applied to the span between Piers I and II. It consistedof 15 locomotives covering the entire clistance between piers and weigh-ing.. 1190.3 tons.
Load III was applied to the span between Piers II and III and to thecantilever arm east of Pier I. It consisted of 12 locomotives covering the
entire span (II-III) and -weighing... ... 944 tons ;
and of four locomotives covering the entire length of cantilever and weigh-ing....... 320.3 tons.
Load IY was applied to the adjacent spans of span (II-III) and consisted
of nine locomotives from Pier II eastward, weighing... 690.2 tons;
and of nine locomotives from Pier III westward, weighing. 715.5 tons.
Load Y was applied to the span between Piers III and IY, and consistedof 11 locomotives covering the entire length of span and weighing.. ..825.2 tons.
Load YI consisted of 18 locomotives coupled together, weighing 1405.7 tons.
This train, moving, at a speed of 30 miles per hour, entered the bridge atthe west end and was stopped at the east end within a distance as short as
practicable. The deflections under the rapidly moving load did not exceed the
maximum deflections under static load.
i
Observations taken on the empty structure immediately after the testshowed that no permanent deflections had taken place.
The vibrations under the running test were as moderate as could beexpected, even from such massive spans.
The behavior of the entire structure under the different tests made wasaltogether very satisfactory. ' • > ■
Respectfully submitted,
ROBERT MOORE,
C. L. STROBEL,
- G. BOUSCAREN,
'' <r ‘ 1 ' The Committee.
: «:r
LOCOMOTIVES USED IN TESTS.
Position inTrain.
Railroad.
Number.
Kind.
Weight in Tons.
1
K. C., M. & B. R. R.
34
10 wheel
85.5
2
(1
23
10
85.5
3
it
35
10 “
85.5
4
it
31
10 “
85.5
5
it
32
10 “
85.5
6
30
10 “
85.5
7
K. C„ Ft. S. & M. R. R.
96
Switch
67.5
8
97
67.5
9
89
it
67.5
to
tt
23
it
67.5
11
I. C. R. R.
1159
8 wheel
78.5
12
L. N. O. & T. R. R.
55
10
82.5
13
N. N. & M. Y. R. R.
605
10 ••
92.3
14
M. &C. R. R. 0
198
8 “
71.0
15
T. M. Ry.
201
10 “
83.0
16
St. L., I. M. & S. Ry.
475
8 “
74.0
17
L. R. & M. R. R.
14
8 "
68.4
18
L. & N. R. R.
321
Switch
73.0
Total.
1405.7
TABULATED STATEMENT OF RESULTS OF TESTS MADE ON THEMEMPHIS BRIDGE, MAY 12, 1892.
Deflections in Feet.
♦ u.
Points Observed.
1st Load,342 tons.
2d Load1190.3 tons
3d Load,944 tons.320.3 “
4th Load,690.2 tons.715.5 “
5th Load,825.2 tons.
6th, Run-ning Load,1405.7 tons
■=-••■ ■■ 1 if":
I 1 r\
Centre of cantilever span.,.
In.
_
0.015
■+
0.025
—
0.020
0.000
_
0.010
Vs.
—
0.010
+
0.025
—
0.020
0.000
—
0.010
- 0.200
West end of 1st cantilever,
IN.
+
0.030
—
0.200
+
0.030
—
0.060
+
0.020
span (I— II). ; .
i s.
+
0.020
—
0.200
+
0.020
0.060
+
0.020
Centre of intermediate span
IN.
+
0.010
_
0.350
+
0.070
—
0.270
0.000
- 0.350
(I-II).
is.
+
0.010
—
0.380
+
0.050
—
0.280
—
0.020
East end of 2d cantilever,
IN.
0.000
_
0.240
+
0.100
—
0.250
_
0.040
span (I-II)..
S S.
l
0.000
-
0.240
+
0.100
—
0.250
-
0.040
Centre of span (II-III).
(N.
( S.
0.000
0.000
+
+
0.090
0.090
—
0.170
0.170
+
+
0.160
0.160
+
+
0.080
0.080
- 0.130
West end of cantilever, span
IN.
0.000
_
0.040
4~
0.120
_
0.270
—
0.200
(III-IV).
) s.
0.000
-
0.050
+
0.110
—
0.270
—
0.200
- 0.240
Centre of intermediate span
IN.
_
0.010
_
0.030
+
0.090
—
0.220
—
0.210
(III-IV).
f S.
0.000
—
0.040
+
0.070
—
0.270
0.210
Movements of Roller Bearings, in Feet.
Points Observed.
1st Load.
2d Load.
3d Load.
4th Load.
5th Load.
North rollers on Pier II.
0.003 E.
0.025 W.
0.048 E.
0.039 W.
0.008 E.
South “ “ " “.
0.003 E.
0.025 W.
0.047 E.
0.040 W.
0.010 W.
(T