SOUTHERN RAILWAY COMPANY IN RE ACCIDENT NEAR EDENTON, N. C., ON
JULY 5, 1957
July 5, 1957
Edenton, N. C.
Diesel-electric units 1605 and 1610
76 cars, caboose
Less than 10 m. p. h.
Timetable and train orders
Single; tangent; level
2 killed; 3 injured
Failure of trestle
It is recommended that:
The Norfolk Southern Railway immediately arrange an inspection
of the trestle by competent engineers to determine the present
Any member of the structure disclosed to have deteriorated to
such an extent that it can no longer be relied upon to perform
its intended function, be replaced at once.
The carrier immediately initiate an adequate maintenance program
and periodic inspection of the trestle.
THE MATTER OF MAKING ACCIDENT INVESTIGATION REPORTS UNDER THE
ACCIDENT REPORTS ACT OF MAY 6, 1910.
SOUTHERN RAILWAY COMPANY
near Edenton, N. C., on July 5, 1957, caused by failure of a trestle.
OP THE COMMISSION 1
July 5, 1957, there was a derailment of a freight train on the
Norfolk Southern Railway, which resulted in the death of two train-service
employees, and the injury of a road foreman of engines and two
No. 3763 Norfolk Southern Railway Edenton, N. C. July 5, 1957
of Accident and Method of Operation
accident occurred on that part of the Norfolk District extending
between Marsden, N. C., and Norfolk, Va., 124.4 miles, a single-track
line over which trains are operated by timetable and train orders.
There is no block system in use. The accident occurred on the
main track 4.6 miles south of Edenton and 1.27 miles south of
the north end of a trestle which spans Albemarle Sound. The track
on the trestle is tangent and the grade is level at the point
maximum authorized speed in the vicinity of the point of accident
is 10 miles per hour.
open-deck trestle originally consisted of 2,131 untreated cypress
and pine full-pile bents and was completed in 1910. It is 5.05
miles In length. Each bent consisted of four batter piles and
to plumb piles having a diameter at the water line of from 12
inches to 14 inches, a 12-inch by 12-inch cap, two 3-inch by 10-inch
diagonal sway braces, and two 3-inch by 12-inch horizontal sash
braces. The batter of the outside batter piles was 3:12 and of
the inner batter piles 1-1/2:12. The cap was secured to the top
of each pile by a 3/4-inch drift bolt. At the cap, the center-lines
of the piles were located, respectively, 1-1/2 feet, 3-1/2 feet,
and 5-1/2 feet from the vertical center-line of the bent. The
top ends and the bottom ends of the diagonal sway braces were
secured to the ends of the cap and outside batter piles, respectively,
by 3/4-inch bolts. These braces were secured to the other piles
by 1/2-inch by 8-inch spikes. The bottom ends of these braces
were located approximately at the low-tide water level. The sash
braces were located beneath the sway braces and were secured to
each pile by a 3/4-inch bolt.
bents were 12 feet 6 inches apart and were connected by four 8-inch
by 16-inch by 25-foot untreated fir stringers located on the tops
of the caps. Two stringers were located on each side of the vertical
center-line of the bent at right angles to the cap and with the
16-inch dimension in a vertical position. The two stringers were
secured together by 3/4-inch bolts with spacers between and were
secured to the cap of each bent by a 3/4-inch drift bolt extending
vertically through the outside stringer. The joints of the stringers
were staggered and were located at the caps. The inside faces
of the inside stringers were located 1 foot 9-3/4 inches from
the vertical center-lines of the bents. The 7-inch by 8-inch by
9-foot untreated white oak ties were placed on the stringers at
a distance of 14 inches between center-lines. They were secured
to the inside stringers by 1/2-inch by 12-inch spikes. The rails
were single-spiked. No tie plates were provided. The tops of the
rails were approximately 15-1/2 feet above the low-tide water
level. Diagonal braces extending between bents in alternate bays
were provided. These braces had a section of 3 inches by 12 inches
and were secured by 3/4-inch drift bolts to the outside batter
piles at the top ends and at the water level. A 3/4-inch bolt
secured the braces on each side at the center. Untreated cypress
and fir guard rails were provided and were secured to the ends
of the ties by 5/8-inch spikes.
the period extending from 1910 through 1949, inclusive, 8 bents
were replaced with full-pile treated pine bents, and the plies
of 2,093 bents were cut off approximately at the low-tide water
level and untreated wood frames were applied. Each frame consists
of a 12-inch by 12-inch base sill, two 12-inch by 12-inch batter
posts having a batter of 3:12, two 12-inch by 12-inch plumb posts,
a 12-inch by 12-inch cap, and two 3-inch by 10-inch diagonal sway
braces. The sill is secured to each pile by a 3/4-inch drift bolt.
Each post is secured to the sill by two 3/4-inch drift bolt. At
the cap, the centers of the batter posts and the plump posts are,
respectively, 4 feet 6 inches and 2 feet 6 inches from the vertical
center-line of the bent. The tope ends and the bottom ends of
the diagonal sway braces are secured to the ends of the cap and
the ends of the sill, respectively, by 3/4-inch bolts. These braces
are secured to the plump posts by 1/2-inch by 8-inch spikes. Diagonal
braces extending between the frame-type bents are provided. These
braces have a section of 3 inches by 10 Inches and are secured
by 3/4-inch bolts to the batter posts at the top and bottom ends.
A 3/4-inch bolt secures the braces on each side at the center.
Two horizontal 4-inch by 12-Inch sash braces are provided at the
top ends of the piles of a bent and two horizontal diagonal braces
are provided between the sills of adjacent bents where considered
necessary. No sway braces are provided between the water level
and the mud line. On bents that have been reworked since 1955,
the centers of the batter posts and the plumb posts are, respectively,
4 feet and 2 feet from the vertical center-line of the bent, and
the sway braces are secured to the plumb posts by 3/4-inch bolts.
the period extending between 1919 and 1923, inclusive, a third
stringer was applied on each side of the trestle. The three stringers
are secured together by eight 3/4-inch bolts with spacers between,
and are secured to the cap of each bent by a 3/4-inch drift bolt
extending vertically through the middle stringer. The joints of
the stringers are staggered and are located at the caps. The center-lines
of the middle stringers are located 2 feet 5-1/2 inches from the
vertical center-line of the bent.
1949, a program of replacing bents with full-pile treated pine
bents and wood stringers with fabricated steel stringers was initiated.
Each of these bents consists of four batter piles and two plumb
piles, a 12-inch by 12-inch cap, two 3-inch by 10-inch diagonal
sway braces, and two 3-inch by 10-inch horizontal sash braces.
All members of the bent are treated pine. The plies comply with
the American Railway Engineering Association specifications for
wood piles. The batter of the outside batter piles is 3:12 and
of the inner batter plies 1-1/2:12. The cap is secured to the
top of each pile by a 3/4-inch drift bolt. At the cap, the centerlines
of the piles are located, respectively, 1 foot 1-1/2 Inches, 3
feet 3-1/2 inches, and 5 feet 6-1/2 inches from the vertical center-line
of the bent. The diagonal sway braces are secured by 3/4-inch
bolts to the ends of the caps and outside batter piles at the
top ends and to the outside batter piles at the bottom ends. These
braces are secured to the other plies by 3/4-inch bolts. The bottom
ends of these braces are located approximately at the low-tide
water level. The sash braces are located beneath the sway braces
and are secured to each pile by a 3/4 -inch bolt. The fabricated
steel stringers consist of two 16-inch by 7-inch WF 1-beam sections
25 feet in length weighing 45 pounds per foot. The 16-inch dimension
is placed vertically. The sections are spaced 15 inches apart
by 15-inch channels 8 inches in length bolted to the webs of the
section. A steel plate 1/2 inch by 18 Inches is provided at each
cap location. A 3-inch by 3-inch angle 22-1/2 inches In length
is located on each side of the cap and secures the stringer from
longitudinal movement. The plate and angles are bolted to the
bottom flanges of the sections. A 7/8-inch lag screw secures the
plate to the cap. Where steel stringers are applied, 8-inch by
8-inch by 9-foot treated ties are provided. Clip anchors securing
ties to the flanges of the sections are provided at every fourth
the time of the accident 19 of the bents of the trestle contained
original full piles, approximately 82 percent of the bents were
of the frame type, and the other bents were of the full-pile treated
64, a south-bound second-class freight train consisted of diesel-electric
units 1605 and 1610, coupled in multiple-unit control, 76 cars,
and a caboose. This train departed from Marsden, the last open
office, at 9:20 p.m., on July 4, 20 minutes late, and while moving
over the trestle at a speed of less than 10 miles per hour, the
trestle failed under the rear truck of the first diesel-electric
unit and the front truck of the second diesel-electric unit. Both
units and the first car feel through the trestle. The second car
stopped with the front end extending over the damaged portion
of the trestle. Both diesel-electric units and the first car were
badly damaged. The third car was somewhat damaged.
engineer and the conductor were killed. The fireman, a brakeman,
and a road foreman of engines were injured.
weather was clear at the time of the accident, which occurred
about 12:02 a.m.
units 1605 and 1610 are of the road-switcher type. Each unit is
mounted on two 6-wheel trucks the wheelbase of each truck is 11
feet 6 inches. The distance between truck centers is 32 feet 3
inches. The specified total weight of each unit in working order
is 289,900 pounds.
No. 64 was approaching the point where the accident occurred,
the engineer and the fireman were in the control compartment of
the first diesel-electric unit, and the conductor, the brakeman,
and a road foreman of engines were in the control compartment
of the second diesel-electric unit. The flagman was in the caboose.
The control compartments were located at the south end of the
first diesel-electric unit and at the north end of the second
diesel-electric unit. The brakes of the train had been tested
and had functioned properly when used en route. The fireman and
the brakeman said the first that they became aware of anything
being wrong was when they heard timbers breaking. The road foreman
said that the second diesel-electric unit swayed considerably
immediately before the accident occurred. The surviving members
of the crew said that the trestle filled under the south end of
the first diesel-electric unit and the north end of the second
diesel-electric unit. They said that no brake application was
made immediately before the accident occurred. They estimated
that the speed of the train at the time of the accident was less
than 10 miles per hour.
of the equipment after the accident occurred disclosed no defects
which could have caused or contributed to the cause of the accident.
Examination of the control equipment of the first diesel-electric
unit disclosed that the isolation switch was in off position,
the throttle was in closed position, the automatic brake valve
was in emergency position, and the independent brake valve was
in full application position, indicating that the engineer took
action to stop the train at the time the accident occurred. The
tapes of the speed-recording devices of both diesel-electric units
were water-soaked and, as a result, were damaged to the extent
that the recorded speed of the train immediately before the accident
occurred could not be determined.
the vicinity of the point of accident the trestle consisted of
frame-type bents. The penetration of the plies was approximately
40 feet. At low tide the depth of the water is about 20 feet.
The water level varies approximately 2 feet. There was no indication
that equipment had been derailed before the trestle *** The frames
of 11 bents were destroyed when the accident occurred. Twenty-one
piles of these bents remained in place. Since only about 20 percent
of the trestle members involved In the accident were recovered,
the sequence of events that led to the failure of the trestle
could not definitely be determined. There was no indication of
damage to the plies by marine borers. One batter post of a frame
involved in the accident was decayed near the bottom end to the
extent that only approximately 30 percent of the original cross-sectional
area was effective in bearing the load applied to the post. (See
of the remaining portion of the trestle from the deck after the
accident occurred disclosed that a large number of ties were in
various states of decay. None of the decayed ties were adjacent
to each other. A number of stringers were decayed but not more
than one decayed stringer was found in any group of three stringers
on either side of the trestle. Examination from the water level
disclosed that a number of piles-of the bents containing the original
full piles were in various states of decay. The outside batter
pile of one of these bents had spilt longitudinally and had decayed
near the water line to the extant that it had failed. Two other
piles In this bent were considerably decayed. (See Plate 2 and
3.) The tops of the plies supporting the frames of a considerable
number of frame-type bents had deteriorated" to the extent that
the sills were not bearing on them. Some of these bends had as
many as three piles in that condition with results that the sill
was subjected to high bending stresses and three piles were bearing
a load which should have been distributed over six piles. A considerable
number of frame-type bents were found in which the sill was not
bearing on the outside batter pile. In some cases the pile was
missing or had moved from its proper location, and in other cases
the pile was in its proper location but the top of the pile had
deteriorated to the extent that it was not in contact with the
sill. (See Plates 4 and 5.) Under that condition the unsupported
end of the sill was required to withstand the force transmitted
by the batter post and high bending stresses were produced in
the sill where it was supported by the inside better post. Two
bents were found in which the sills had failed because the top
of the outside batter pile was not in contact with the sill. (See
Plates 6 and 7.) In each case the outside batter pile was in its
proper location and prevented the sill from breaking off completely.
It is probably in each of these cases that if the outside batter
pile had moved from ts proper location or had been missing the
bend would have failed.
trestle is maintained by two regularly assigned bridge crews.
Each crew inspects a portion of the trestle each working day.
Bridge patrolmen inspect the trestle from a velocipede car after
each train movement. Weekly inspection are made from the deck
by a bridge supervisor who is frequently accompanied by an assistant
chief engineer. These inspections are made by riding trains and
track motor-cars, and by walking on the deck of the trestle. Inspections
from the water level are made by boat. The last inspection made
from the deck before the accident occurred was on July 3, 1957.
No inspection had been made by boat since January 1957.
the period extending between 1949 and 1956, inclusive, 274 original
full-pile and frame-type bents were replaced with full-pile treated
pine bents, and steel stringers having a total length of approximately
5,800 feet were applied. At the time of the accident the carrier's
replacement program for 1957 indicated that 93 bents were to be
replaced and that steel stringers having a total length of 400
feet were to be applied during that year. If the 1957 rate of
replacement of bents is maintained in the future, it would require
19 years for the replacement of all original full-pile and frame-type
this Commission has no jurisdiction over the maintenance and repair
of bridges or trestles, our investigation discloses that through
lack of maintenance the piling of this trestle is deteriorated
to a dangerous degree.
accident was caused by failure of a trestle.
That the Norfolk Southern Railway Company immediately arrange
for a thorough and systematic inspection of the trestle by competent
engineers to determine the present overall condition of the entire
structure and Its ability to withstand the traffic loads to which
it may be subjected.
That any member of the structure disclosed by this inspection
to have deteriorated to such an extent that it can no longer be
relied upon to perform its intended function, as well as those
portions of the trestle found during the investigation of this
accident, some of which are Illustrated in this report, to be
in such an advanced state of deterioration as obviously to necessitate
their renewal, be replaced immediately, in order to preclude the
possibility of recurrence of the type of failure that resulted
in collapse of the structure.
That the carrier immediately initiate an adequate maintenance
program, including frequent periodic inspections of the entire
structure by competent personnel, to insure that the trestle is
maintained at all times in safe and suitable condition to carry
the traffic which operates over it.
at Washington, D. C., this twenty-fifth day or September, 1957.
the Commission, Commissioner Tuggle.
HAROLD D. McCOY,
1. Showing the extent of decay found at the bottom end of a better
post of one of the frame-type bents involved in the accident.
2. Showing failure of the east outside batter pile of an original
full-pile bent because of decay; also shown longitudinal split.
3. Showing extent of decay in other piles of the original full-pile
bent shown in Plate 2.
4. Showing outside batter piles of frame-type bents which have
moved from proper location or are missing.
5. The top of the outside batter pile in the foreground had deteriorated
to the extent that the base sill is not bearing on it. Note that
the nearest point of support on the base sill is provided by the
pile under the plum post.
7 Showing failure of base sills of frame-type bents because of
deterioration of the tops of the outside batter piles.
Under authority of section 17 (2) of the Interstate Commerce Act
the above-entitled proceeding was referred by the Commission to
Commissioner Tuggle for consideration and disposition.