Cable drum schedule: what it is and how to make one
A cable drum schedule lists every cable drum on a job and the cables to be cut from each one, in cutting order, with each cut length and the balance left on the drum after it. It is made from the cable schedule and the drum register, and it tells the crew which drum to pull each cable from.
What is a cable drum schedule?
It is the plan that matches cables to drums: for each drum (a reel, in North America), which cable numbers are cut from it, how long each piece is, and what is left on the drum afterwards.
The designer's cable schedule says what cables the job needs. The drum register says what cable is on site. The drum schedule joins the two, so that every cable has a drum before anyone cuts, part drums and offcuts are used before full drums are opened, and whatever the stock cannot cover is ordered in time. Method statements for cable installation refer to it directly: one published method statement for MV cable pulling says the cable drum intended for pulling "shall be identified as per that indicated in the drum schedule".
On large EPC jobs a cable or materials engineer often prepares it before ordering; on mid-size jobs the contractor's site engineer or project coordinator keeps it, most often in Excel. Either way, it is only right for the revision of the cable schedule it was planned against.
What goes in a drum schedule?
One block per drum, grouped by cable type, with a row for every cable to be cut from it and the running balance of the drum.
| Column | What it holds |
|---|---|
| Drum | The drum number, with the length received, the balance now, where it is stored and where it came from. |
| Cable type | Cores, size, conductor, insulation and armour, for example 4C × 95 mm² Cu XLPE/SWA/LSZH. Drums and cables are matched on it. |
| Seq | The order to cut in. |
| Cable no. | The cable number from the cable schedule. |
| From and To | The two ends, so the crew can check the cable against the drawings. |
| Cut | The schedule length plus the allowances for pulling and cutting. |
| Status | To cut, cut or installed. |
| Balance after | What the drum holds after this cut. The last row is the leftover, which should be close to nothing or long enough to reuse. |
| Notes | Date cut, sheath marks at each end of the piece, anything the crew must know. |
Above the table goes a title block: the project and job number, the revision of the cable schedule it was planned against, the date it was issued, and the allowances used, so anyone reading it knows what it assumed.
An example
This is part of the drum schedule for Drumplan's sample project, an invented water treatment works with 99 cables in 8 cable types and 13 drums, as it stood when Rev C of the cable schedule arrived, with 47 cables installed and 14 cut. It is exactly what Drumplan exports. DR-01 has nothing cut yet. DR-03 had 500 m: FB-P-006 has been cut and installed (the crew recorded sheath marks 500 to 387, so 113 m), two more cables are still to cut, and 212 m will be left for reuse.
| Drum | Cable type | Seq | Cable no. | From | To | Cut (m) | Status | Balance after (m) | Notes |
|---|---|---|---|---|---|---|---|---|---|
| 4C × 185 mm² Cu XLPE/SWA/LSZH 0.6/1 kV | |||||||||
| DR-01 | 4C × 185 | Received 250 m · balance now 250 m · Laydown A · Anixter UK | |||||||
| 1 | FB-P-001A | LVSB-1 | MCC-B | 97 | To cut | 153 | |||
| 2 | FB-P-001B | LVSB-1 | MCC-B | 97 | To cut | 56 | |||
| Left on drum | 56 | Leftover: reusable | |||||||
| 4C × 16 mm² Cu XLPE/SWA/LSZH 0.6/1 kV | |||||||||
| DR-03 | 4C × 16 | Received 500 m · balance now 387 m · Laydown A · Anixter UK | |||||||
| ✓ | FB-P-006 | MCC-B | WRP-1 | 113 | Installed | 2026-09-10; marks 500 to 387 | |||
| 1 | FB-P-007 | MCC-B | WRP-2 | 119 | To cut | 268 | |||
| 2 | FB-P-008 | MCC-B | DB-FB | 56 | To cut | 212 | |||
| Left on drum | 212 | Leftover: reusable | |||||||
Drum schedule, cable schedule, drum register and drum card: what is the difference?
The cable schedule lists the cables, the drum register lists the drums, the drum schedule allocates one to the other, and a drum card is the drum schedule for a single drum, printed for the crew.
| Document | One row per | Made by | Used for |
|---|---|---|---|
| Cable schedule | Cable: number, from, to, type, length | The designer or consultant, issued in revisions (Rev A, B, C) | What must be installed |
| Drum register | Drum: number, type, length received, balance, location | Stores or the site engineer | What cable is on site and on order |
| Drum schedule | Cut: drum, cable, cut length, balance after | The contractor's engineer, from the two above | Which cable comes off which drum, and what to order |
| Drum card | Cut, for one drum only | Printed from the drum schedule | Goes with the drum: the crew cuts in order and writes down the sheath marks |
| Order list | Drum to buy: type and length | From the drum schedule's shortfall | Buying what the stock cannot cover |
How do you make a drum schedule?
Take the current cable schedule and the list of drums, group both by cable type, add allowances to the cable lengths, and allocate the cables to the drums so that part drums and offcuts are used first and every drum ends with either nothing or a reusable length. Whatever does not fit becomes the order.
- Start from the current revision of the cable schedule and note its letter. The drum schedule is only right for that revision.
- List every drum you can cut from: full drums, part drums at their real balance, offcuts long enough to use, and drums on order.
- Group cables and drums by cable type. The same cable is often written several ways ("4C x 95mm² XLPE/SWA" and "4 core 95 sq mm SWA"); treat them as one type.
- Work out cut lengths. Add an allowance per cut for the pulling end and cut-off, and a percentage only if the schedule lengths do not already include spare. Pathnovo's cable schedule template, for example, already includes 10% spare and about 2 m per end.
- Keep a reserve on each drum for length tolerance and measuring error.
- Allocate. Offcuts and part drums first, then fill each drum with the combination of cables that uses it best. A leftover should be close to nothing or long enough for another cable; anything in between is scrap.
- Turn the shortfall into the order list, in drum lengths your supplier sells, early enough for delivery.
- Issue it with a drum card for each drum, dated and marked with the schedule revision.
Step 6 is the slow part by hand: the number of possible combinations grows very quickly with the number of cables. The cable drum cut list calculator does it for one cable type in your browser; Drumplan does it for the whole schedule and writes the drum schedule, drum cards and order list.
How do you keep a drum schedule up to date on site?
Record every cut against the drum it came from as it happens, work out drum balances from the cuts rather than from the plan, and re-plan only the cables not cut yet against what is really left.
Sites do not cut exactly to plan. A piece is cut a metre too long, a cable comes off a different drum, a part drum turns out shorter than its label, a cable is pulled early with a tray section. If the drum schedule still shows the plan, its balances drift away from the drums and the next allocation is wrong.
Recording a cut by sheath marks
Many cables are printed with sequential length marks along the sheath. The length of a piece is the difference between the marks at its two ends: marks 500 and 387 mean a 113 m piece. Check which way the marks run on each drum, because some count up and some count down, and check the spacing and tolerance with the manufacturer. Writing both marks on the drum card gives a record that can be checked later.
How much cable is left on a part drum?
The record answers it: the length received less every cut taken from it, which is the balance on the drum card. Check it against the drum when you can, by the sheath marks or by measuring, and correct the record when they differ. Working it out from the drum's dimensions gives only an estimate.
What happens to the drum schedule when the cable schedule is revised?
The allocation is only right for the revision it was planned against. When a new revision arrives after cutting has started, every change has to be checked against the work already done, and the cables not cut yet have to be re-planned against the stock actually left.
- Cut pieces that are now too short go back to stock as offcuts, and the cable needs a new cut.
- Installed cables that were deleted, or re-routed or changed to another type and must be replaced, are abortive work, and the record of them supports a variation claim.
- Drum cards that change must be reprinted, and only those.
- The order list changes, sometimes from nothing to buy to several drums.
Re-planning from scratch after a revision moves cables the crew already has cards for. Keeping the issued drums where they still work is usually better. In Drumplan's sample project, Rev C changes 16 cables and 12 of those changes hit work already done. Keeping the issued drums moves 3 runs; re-planning everything would move 15 and buy no less cable.
Revision reconciliation, the abortive work list and the revision impact report are part of Drumplan Pro. Every Pro feature is open in the sample project, where you can import Rev C yourself.
Make your drum schedule from your own spreadsheets
Import the cable schedule you were issued and your drum register, as Excel or CSV. Drumplan reads the columns, merges the spellings of each cable type, allocates every cable, and exports the drum schedule and order list to Excel with a printable drum card for each drum. Planning is free, with no account, and your spreadsheets are never uploaded.
Sources
- The Engineers Blog, method statement for MV cable pulling and installation, 15 October 2022 ("identified as per that indicated in the drum schedule"): engineersblog.net, checked 28 September 2026.
- Pathnovo, free cable schedule template (Drum Number column; cable length including 10% spare, about 2 m per end): pathnovo.com, checked 28 September 2026.
- Kingforyou Cable, cable jacket markings guide, 15 July 2026 (sequential length marks may count up or down; confirm interval and tolerance): kingforyoucable.com, checked 28 September 2026.
- The example and the sample numbers: Drumplan's exporter and planning engine, run on the sample project.