Herrenknecht HK 250T
Maxi rig, 250 ton pullbackOur heavyweight for long, large-diameter and sea channel crossings.
CAPABILITY 04 / 06 · Pipeline stringing & welding
ONE STRING. ONE PULL.
Automatic welding, testing and stringing of the carrier pipe so the pullback is a single continuous operation with no stops for joints.
THE SCOPE
Pipeline stringing & welding
Pullback cannot wait for a welder. Once the reamed bore is open, the pipe must go in continuously or the hole begins to close. Crossroad builds the full pipe string before pullback: HDPE butt-fused on automatic fusion machines, steel welded and NDT-inspected on the string line, each joint recorded against its position in the string.
The string is laid out on rollers on the exit side, aligned with the bore exit angle, and hydrotested or pre-tested as the specification requires before the pull begins. Where the site cannot accommodate the full length, the string is built in sections with a planned tie-in stop. We coordinate the pipe supply, the coating and the testing contractor so the string is ready the day the reamer breaks through.
WHAT WE DELIVER
IN SCOPE ON EVERY JOB
- 01HDPE butt fusion on automatic hydraulic machines with fusion data logging
- 02Steel pipeline welding with NDT and coating repair on the string line
- 03Roller and crane stringing aligned to the exit angle
- 04Pre-pull hydrotest and mandrel or gauge-plate checks
- 05Pull head fabrication, swivel and breakaway link selection
- 06Bundled strings and casing-with-carrier installations
HOW IT RUNS
SEQUENCE ON SITE
01
Pipe receipt
Pipe is inspected, logged and laid out on the string line in pull order.
02
Fusion or welding
Joints are made on automatic equipment with every parameter recorded; steel joints receive NDT.
03
Test and gauge
The string is pressure tested and gauged before it ever enters the ground.
04
Pullback ready
Pull head, swivel and rollers are set so the string meets the exit angle without stress.
See the full four-stage bore animated on the home page, or size your own crossing with the HDD tools.
IRON ON THE JOB
EQUIPMENT WE BRING
Ditch Witch JT 100
Midi rig, 100k lbs pullbackThe workhorse for utility corridors and mid-range road crossings.
Automatic Welding Plant
Continuous pipe stringAutomated welding for consistent, tested joints before pullback.
ON RECORD
CROSSINGS LIKE YOURS
STRAIGHT ANSWERS
QUESTIONS WE GET ASKED
Engineers answer every enquiry. If your question is not here, send it over.
01Can the pipe be welded during the pull?
It should not be. Every stop during pullback lets the bore relax and raises the pull load. We build and test the complete string first, and if the site is too short for the full length we design a single tie-in stop with the pipe pre-positioned.
02Do you supply the pipe?
We can install client-supplied pipe or procure it with the project. In both cases the pipe is inspected on receipt and every joint is logged against the string.
03What testing is done before pullback?
A pre-pull pressure test to the specification and a gauge check on steel strings. After pullback the line is tested again as part of handover.
