Ditching over buried lines

The method of ditching over a buried line involves making a hole, in advance of ditching, down to a level near a section of the buried line lying at the intersection with a proposed trench, spanning the line section with a line protector, and driving a ditching machine so that its excavating member makes the trench and in so doing rides in the trench over the protector and above the line section.

REFERENCE TO RELATED APPLICATION 
This application is related to Applicant's copending application Ser. No. 
124,159 filed on Feb. 25, 1980. 
BACKGROUND OF THE INVENTION 
This invention relates to the art of ditching in areas traversed by 
underground lines, such as buried pipelines, telephone and power cables, 
gas lines, etc. 
Machines are now widely used for excavating such ditches and for laying 
such underground lines. But when such ditching machines are used in 
terrains traversed by buried lines, care must be exercised else the 
excavating member of the ditching machine can cut such existing buried 
lines. 
At present, the intersection between a buried line and a proposed trench is 
excavated manually while the trenching machine is allowed to excavate only 
up to and on either side of said intersection so as not to cut the buried 
line. Such a procedure slows down considerably the speed within which the 
trench can be constructed. 
SUMMARY OF THE INVENTION 
The method of making a ditch which will cross a buried line comprises 
making a hole in advance of ditching down to a section of the buried line 
at the point of intersection with said ditch, spanning the line with a 
line protector, and moving an excavating member of a ditching machine over 
the protector, thereby protecting the line section during the trenching 
operation. 
The line protector comprises a pair of spaced-apart pads supporting a 
bridge structure which has a pair of end shoulders. At least one anchor 
extends vertically downwardly from each pad. 
It is a main object of the present invention to considerably reduce the 
amount of earth required to be removed in and around the intersection 
between a buried line and a ditch under construction, and to allow a 
ditching machine to ride over such intersection, thereby to greatly 
expedite the construction of the trench as well as to considerably reduce 
the cost thereof.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
Referring to the drawings, it is desired to make a ditch 38 (FIGS. 6-7) 
having a bottom 37 that would intersect an existing buried line, such as a 
pipeline 36 for the purpose of laying a new line therein, such as a 
pipeline 50. 
This is accomplished, in accordance with the invention, by first digging 
out in the ground a hole 30 in advance of the ditching operation in order 
to detect and preferably expose a section 36' of the buried pipe 36 at the 
intersection between pipeline 36 and the trench 38 to be constructed. 
After hole 30 is dug out, which could be done manually with a shovel, then 
a line protector, generally designated as 10, is suitably disposed at the 
bottom of hole 30 in order to span over the pipe section 36' (FIG. 5). 
Line protector 10 is constructed to protect pipe section 36' and to 
support a ditch digging machine 40 (FIG. 6). 
Line protector 10 serves as an arch structure and comprises a pair of 
shaped-apart horizontal pads 12, 14 supporting a generally 
semi-cylindrical bridge 16 and a pair of semi-circular end shoulders 17, 
18. Bridge 16 has a longitudinal center axis O and is sustained by a 
radius R. One or more anchors 20 extend vertically downwardly from each of 
pads 12, 14. 
In use, after the hole 30 is dug out, the line protector 10 is positioned 
so that its longitudinal axis O lies along the longitudinal axis of the 
exposed pipe section 36', and the anchors 20 are anchored into the bottom 
ground under hole 30 (FIGS. 5, 6). 
The ditch digging machine 40 is then moved in the direction of arrow 41 to 
dig out the trench 38. The particular ditch digging machine 40 is 
illustrated as having a continuous chain 42 on which scoops or buckets 43 
are mounted, and the chain is movable in a counter-clockwise direction, as 
indicated by the arrows. 
As the machine 40 moves from left to right (as viewed in FIG. 6), it 
excavates the trench 38 of desired width and at a depth 37. When it 
reaches the intersection with pipe section 36', the chain 42 will ride 
over the bridge 16. End shoulders 17 and 18 prevent the accidental 
slipping off of chain 42 and its buckets 43, which otherwise would cut the 
pipe section 36' lying under the pipe protector 10. After the trench 38 is 
excavated, the desired pipeline 50 is laid therein. 
It will be appreciated that the ditch excavating machine 40 can move over 
the trench-pipe intersection (36, 37) without interruption, in accordance 
with the invention, in the direction of arrow 41, as if the buried pipe 36 
did not exist. Previously, machine 40 had to move towards such 
intersection from the opposite directions but not over such intersection.