fig1 shows an old pipe 2 that is shattered by means of a pneumatically driven ram - boring machine 3 and extends in the ground 1 . the ram - boring machine 3 pulls a pipeline conduit 5 that is composed of individual pipes 4 . each individual pipe comprises a sleeve 5 on one end and a tapered end 6 that engages into the sleeve 5 of the preceding pipe 4 . the ram - boring machine 3 is inserted into the old pipe 2 from the channel shaft 7 , with the required energy for the ramboring machine 3 being supplied via a compressed air hose 8 that extends through the pipeline conduit formed by the individual pipes 4 . in order to rigidly connect the pipeline conduit consisting of the individual pipes 4 to additional pipes 4 as well as the ram - boring machine 3 , a chain 9 that is guided through an opening 13 in a base plate / tensioning frame 11 , a pipeline conduit connecting device is fastened to the ram - boring machine . the pipeline conduit connecting device 10 can be attached to the end of the last individual pipe 4 by means of an exchangeable adapter 12 that is adapted to the pipe diameter . the compressed air hose 8 and the chain 9 extend toward the outside through the slot - like opening 13 such that the tensioning unit can be removed from the region between the pipeline conduit that has already been drawn in and the pipeline conduit that still must be drawn in so as to introduce an additional pipe to be drawn in . a chain wheel 14 that is realized in the form of a sprocket wheel is arranged in rotatable fashion on the base plate within the region of the opening 13 . this sprocket wheel comprises a reverse rotation lock in the form of a toothed locking wheel 15 and a ratchet mechanism 16 that cooperates with said locking wheel . the ratchet mechanism 16 can be locked by means of a hand lever 17 . one respective hydraulic piston / cylinder unit 18 is arranged to both sides of the chain wheel 14 and fastened to the base plate 11 with one end . a lateral shaft 20 is fastened to the ends of the piston rods 19 . this lateral shaft carries rollers 21 that are guided in guides 22 on the base plate 11 as well as a deflection roller 23 in its center . return springs 24 that return the piston rods 19 into the retracted position when the hydraulic piston / cylinder units 18 are not pressurized are arranged parallel to the hydraulic piston / cylinder units 18 on the shaft and on the base plate 11 . naturally , this return motion may also be realized by means of double - action piston / cylinder units . it would also be conceivable to utilize only one hydraulic piston / cylinder unit instead of a hydraulic piston / cylinder pair , with the chain wheel 14 being situated underneath the cylinder and the deflection roller being situated above the cylinder in this case . a removable bolt 25 that prevents the chain 9 from unintentionally falling out of the chain wheel 14 , in particular , when the tension is increased , extends laterally above the chain wheel 14 in fig3 . in addition , a holding device in the form of a jib 26 with a slot 27 is arranged on the base plate 11 . consequently , the device according to the invention functions as follows : it is assumed that an individual pipe 4 was drawn into the ground bore while the old pipe 2 was simultaneously shattered by means of the ram - boring machine 3 , namely to such an extent that the sleeve 5 situated on the end of the pipe ends flush with the wall of the channel shaft 7 . the pipeline conduit connecting device 10 is removed from this individual pipe 4 such that the rear end of said pipe with the sleeve 5 is exposed . an individual pipe 4 stored on the surface can now be advanced via the fluid hose 8 and the chain 9 until the tapered end 6 of this individual pipe can be attached to the sleeve 5 in the channel shaft 7 . subsequently , the adapter 12 is placed into the sleeve 5 of the individual pipe 4 to be attached , and the chain 9 is placed over the sprocket wheel 14 as well as the deflection roller 23 and manually tightened such that one chain link can be secured in the slot 27 on the jib 26 . this manual tightening of the chain 9 is carried out while the piston rods 19 are retracted into the hydraulic piston / cylinder units 18 . if the hydraulic piston / cylinder units 18 are now charged with compressed oil , the chain is tightened while rolling over the chain wheel 14 and the deflection roller 23 . if the chain tension does not suffice after the full stroke shown in fig2 and 3 is reached or the tapered end 6 of the individual pipe 4 is not completely drawn into the sleeve 5 , the deflection roller 23 with the piston rods 19 can be returned into the retracted position under the influence of the return springs 24 without reducing the chain tension within the installed pipeline conduit . this is attained due to the fact that the sprocket wheel 14 is prevented from carrying out a reverse rotation by the ratchet mechanism 16 that engages into the toothed locking wheel 15 . the part of the chain situated between the sprocket wheel 14 and the holding device 26 , 27 is loosened , but can be tightened by securing another chain link in the holding device 26 , 27 . subsequently , the hydraulic piston / cylinder units 18 are subjected to pressure again so as to move the deflection roller 23 into the position shown in fig2 and 3 and tighten the chain anew . this procedure can be repeated until all sleeve connections of the individual pipes 4 are completely pushed into one another and a connection to the ram - boring machine 3 is produced with a predetermined prestress . the ram - boring machine 3 is now actuated again until the preceding pipe 4 that still protrudes into the channel shaft 7 is advanced to such an extent that it ends approximately flush with the channel wall . subsequently , the attachment of an additional pipe 4 is repeated in the previously described fashion . if the prestress of the chain 9 must be eliminated so as to remove the pipeline conduit connecting device 10 from the last individual pipe 4 , it is merely necessary to unlock the ratchet mechanism 16 by means of the hand lever 17 such that the sprocket wheel 14 is able to turn in the opposite direction while the linear tensioning unit is retracted . this causes a corresponding length of the chain 9 to be released . instead of using a linear drive in the form of hydraulic piston / cylinder units 18 , it would also be conceivable to employ a rotary drive for the sprocket wheel 14 , e . g ., a hydraulic motor that allows a gradual tightening of the chain 9 without interruptions . the hydraulic piston / cylinder units may also be replaced with a threaded spindle drive , the spindle of which is either turned manually by means of a ratchet or automatically with the aid of a driving motor . in any case , it is decisive that the tensioning frame is arranged perpendicular to the advance direction . in addition , it is possible to utilize a steel cable instead of a chain 9 . however , holding devices in the form of cable clamps are required in this case . if the rotationally driven winch is formed by a gypsy winch , it is possible to subject the cable to a high tensile stress if the free end of the cable is looped around the capstan several times and pulled with a relatively low tensile force .