Specifying Drawrope: A Practical Guide to Cable Pulling Rope
Drawrope is the quiet workhorse of every ducted network. It is the rope that pulls cable through duct, and the rope that is left behind in the duct afterwards so the next cable can be pulled without digging anything up. Also called draw rope, draw cord, duct rope or simply cable pulling rope, it is one of the cheapest items on a build and one of the most relied upon, because when it snaps or stretches halfway through a long pull, the whole job stops.
For something so routine, drawrope is easy to under-specify. A rope that is too weak for the pull, too stretchy for the run, or too rough for the duct bends will fail at the worst possible moment, mid-pull, with a cable half in the ground. This guide is written for the people speccing and buying it. It covers what drawrope is and why it stays in the duct, the difference between standard and low-stretch rope, the breaking strengths that matter, and how to choose the right rope for the run.
What is drawrope, and why it stays in the duct
Drawrope does two jobs across its life, and the second is the one people forget.
The first is the obvious one: it pulls the cable. The rope is fed or blown through the duct, attached to the cable, and used to haul it along the run. The second is quieter but just as valuable. Once a cable is installed, a fresh length of drawrope is left in the duct alongside it, or in the spare way, ready for the next pull. That leave-in rope is what turns a duct into a reusable pathway: the next cable, the next upgrade, the next operator’s fibre can be pulled through later without opening the ground again. A duct with no rope in it is a duct that needs rodding or re-roping before anything else can happen, which is slow and sometimes impossible on a congested route.
The rope left in the duct is cheaper than a spade. Skipping it is how a ten-minute future pull becomes a half-day of rodding, or a fresh excavation.
This is why specifying drawrope is really two decisions: the rope you pull with today, and the rope you leave in for tomorrow.
Polypropylene, pre-stretched and low-stretch rope
Not all drawrope is the same, and the type matters as much as the size.
Standard drawrope is a three-strand polypropylene rope: strong, light, cheap, resistant to water and rot, and easy to handle and splice. For most pulls this is the drawrope a crew reaches for, and it is what Mountrel’s BlueForce drawrope is built for. Its one weakness is stretch: polypropylene elongates under load, which on a long or heavy pull means effort goes into stretching the rope rather than moving the cable, and a stretched rope can snap back dangerously if it fails.
That is where pre-stretched and low-stretch ropes come in. A pre-stretched rope such as Rope Cabling No.1 is self-tailing and holds its length under load, which gives a more controlled pull and better feel on the winch. For longer underground runs where stretch really matters, a low-stretch rope such as Rope Cabling No.4 keeps elongation down so more of the pulling force reaches the cable. And for recovering a cable or a stuck draw, a heavier recovery rope such as Recovery 4 is built for the higher loads involved. Matching the rope type to the pull is the difference between a clean, controlled installation and a fight.
Breaking strength: the number that matters
The specification that decides whether a rope survives a pull is its breaking strength, and it has to be read against the load of the run, not guessed.
As a working guide, a standard-duty drawrope offers a breaking strength in the region of 4.5 to 5.5kN at 5mm, while a heavy-duty rope steps up to around 6.5kN at 6mm. The rule is simple: the rope’s breaking strength must comfortably exceed the maximum tension the pull will reach, with a sensible safety margin, because the peak load on a pull is not the steady effort but the snatch at a bend or a snag. A rope chosen to match the average pull will fail on the worst metre of it. Size up for long runs, multiple bends, heavy cable and cold weather, all of which raise the tension the rope has to survive.
A common and sensible supply format for leave-in and general pulling is a 6mm polypropylene rope on a 500m wooden drum, which covers most duct runs on a single drum and dispenses cleanly without tangling.
Common failures, and how to avoid them
Most drawrope problems come down to three failure modes, and all three are avoidable at the specification stage.
The first is snapping, almost always from under-specifying the breaking strength for the pull, or from reusing a rope that has already been weakened. The second is stretch, from using a standard polypropylene rope on a long run where a low-stretch rope was needed, which wastes effort and makes the pull unpredictable. The third is abrasion at duct bends, where the rope saws against the duct wall under tension and wears through, which is worse with a rough or damaged rope and on tight bends. Choosing the right rope type and strength, keeping ropes in good condition, and using lubricant on hard pulls addresses all three.
A specification checklist for drawrope
Decide both uses: the rope you pull with now, and the rope you leave in the duct for the next pull.
Match the rope type to the run: standard polypropylene for general pulls, pre-stretched or low-stretch for long or heavy underground runs.
Choose a breaking strength that comfortably exceeds the peak pull tension, with a safety margin for bends, snags and cold.
Size up for long runs, multiple bends and heavy cable, where tension spikes.
Use a recovery-grade rope for recovering cables or freeing a stuck draw.
Pick a practical supply format, such as a 6mm x 500m drum, to cover a run on one drum.
Keep a fresh leave-in rope in every duct so future pulls need no rodding.
Frequently asked questions
What is a drawrope used for?
A drawrope is used to pull cable through duct, and to be left in the duct afterwards so the next cable can be pulled later without digging. It is also called draw rope, draw cord or cable pulling rope.
What breaking strength drawrope do I need?
Enough to comfortably exceed the peak tension of your pull, with a safety margin. As a guide, standard-duty rope is around 4.5 to 5.5kN at 5mm and heavy-duty around 6.5kN at 6mm. Size up for long runs, multiple bends, heavy cable and cold weather.
Is drawrope the same as draw cord?
They refer to the same job. “Draw cord” tends to be used by merchants and for lighter-duty pulling lines, while “drawrope” is the common term for the polypropylene cable pulling rope used in telecoms and utility duct.
Should drawrope be left in the duct?
Yes. Leaving a fresh rope in the duct after a pull means the next cable can be installed without rodding or re-roping, which keeps the duct a reusable pathway and saves significant time later.
What size drawrope is used for telecoms ducts?
A 6mm polypropylene rope, often supplied on a 500m drum, is a common choice for telecoms duct, with 5mm used for lighter pulls and heavier grades where loads are higher. Match the size to the breaking strength the pull needs.
Related Mountrel products
Drawrope and BlueForce drawrope, polypropylene rope for general cable pulling
Rope Cabling No.1, a pre-stretched, self-tailing cabling rope
Rope Cabling No.4, a low-stretch rope for long underground runs
Recovery 4, a heavier rope for cable recovery
Ducts, the pathway the rope runs through
See the full accessories range, and our related guides on specifying cable ducting and specifying fibre drop cable.
Talk to Mountrel about drawrope
Mountrel supplies drawrope and cable pulling rope for UK telecoms and utility networks: standard polypropylene drawrope, pre-stretched and low-stretch cabling ropes, and recovery rope, in practical drum lengths and held in UK stock. If you are specifying rope for a duct network, email the team at sales@mountrel.com and we will help you match the rope type, strength and length to your runs.
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