Rail fatigue calculator
Score a rail duty against NR/L2/OHS/003.
The Network Rail fatigue standard sets triggers and hard limits against the HSE fatigue index for everyone working on its infrastructure, contractors included. This rail fatigue calculator opens on the NR/L2/OHS/003 profile, so the rest, break and duty-length checks and the day and night triggers are the standard's figures, read from the same engine that scores whole rosters. No signup, nothing stored unless you save.
An independent implementation of HSE Research Report RR446 with the NR/L2/OHS/003 figures as the default profile. Not a Network Rail, ORR or HSE product. The general calculator covers every profile.
General calculatorNR/L2/OHS/003 roster checklistFatigue management for rail
One shift is a taster. The rota is the hazard.
Drop the CSV or XLSX your rota tool exports. Every shift is scored in the browser session; nothing is saved until you ask.
Deterministic scoring against HSE RR446 on the Network Rail NR 003 profile. Nothing is stored unless you choose to save. The same engine scores whole rosters in RotaPulse, free up to 10 workers.
What NR/L2/OHS/003 sets, and which kind of number each is
The standard draws a line that matters in the conversation with a principal contractor or an ORR inspector. Hard limits are not to be rostered. Triggers require a documented exceedance assessment and a management plan, after which the work may proceed. Reporting a trigger as a breach, or a limit as a trigger, puts a planner in the wrong conversation. Every figure below is read from the Network Rail NR 003 profile in the engine; the printable roster checklist lists the same figures with the advisory ones.
| Check | Figure | What it means |
|---|---|---|
| Longest period of duty | 12 hours | Hard limit. Not to be rostered beyond this. |
| Rest between booking off and booking on | 12 hours | Hard limit. The calculator's rest-before figure is measured against it. |
| Consecutive duties | 13 in any 14 days | Hard limit. Needs the whole roster, not one duty. |
| Fatigue index, daytime duty | 35 | Trigger. An exceedance assessment and a management plan, then the work may proceed. |
| Fatigue index, night duty | 45 | Trigger. Higher because the index already penalises night work. |
| Risk index, day or night | 1.6 | Trigger, regardless of the time of day. |
| Hours in a rolling seven days | 60 and 72 | Two trigger levels: assessment, then escalated assessment. Needs the roster. |
| Door to door, including travel | 14 hours | Trigger. Enter travel time and the calculator shows effective rest; the roster view checks the door-to-door total. |
| RotaPulse early warning | 28 | Ours, not the standard's: an amber band below the daytime trigger so a roster drifting toward an exceedance is seen in time. |
Source: Network Rail NR/L2/OHS/003 as implemented in published supply-chain procedures. The risk index is the second output of the RR446 method, a relative risk of a fatigue-related error against a reference pattern.
Worked rail examples
Each link loads the duty into the calculator above and scores it. Change one thing and score again: the rest gap, the travel, the prior duties.
Fourth night of a track worker's run
A 12-hour night, booking on at 21:00, with the third and second nights before it on the same times. Safety critical work. The cumulative driver is what moves; the pattern is common on possessions and it is why the standard's night trigger sits where it does.
Load this shift into the calculatorA driver's early turn after a late
Booking on at 04:30 for an eight-hour early turn, having booked off a late turn at 23:00 the night before, with fifty minutes' travel in before booking on. The rest gap is what the standard's hard limit is about, and the travel makes the effective rest shorter still.
Load this shift into the calculatorPossession night with a long drive to site
A ten-hour possession, 21:30 to 07:30, with ninety minutes' travel to the access point and the same duty the night before. Ten rostered hours is inside the duty limit; the door-to-door total is the figure the standard's trigger H is about.
Load this shift into the calculator
Reading a rail result
The Fatigue Index is the estimated probability, as a percentage, that a person on this duty will feel very fatigued at some point during it. The Risk Index is comparative: a relative risk of a fatigue-related error against the reference pattern of 12-hour duties on a two-day, two-night, four-off cycle. The standard sets a trigger on each, and the night trigger on the fatigue index sits higher than the day one.
The result panel names the band as within reference, above reference or high risk, and shows the profile's figures next to the number. A duty under the trigger is not thereby safe, and one over it is not banned: it needs the exceedance declared, assessed and managed in writing. The words pass and fail do not appear here because the standard does not use them either.
What a single duty cannot show
The rolling seven-day hours triggers, the consecutive-duty limit and the door-to-door trigger are roster properties. One duty with two priors can show the rest gap, the break, the duty length and the two indices; it cannot show the week. The upload under the result scores every duty on the roster with each worker's earlier duties as its priors.
It also scores the roster as planned. Rest day working, extended hours and the swap agreed at the mess room door are what RAIB and RSSB keep pointing at, and they only appear when the hours as worked are scored too. Read how the standard sits alongside ORR's fatigue factors on the rail page, and the method in full on the methodology page.
Questions
Is this the Network Rail fatigue calculator?
No. Network Rail does not publish a calculator. NR/L2/OHS/003 requires the fatigue and risk index to be applied and sets triggers and limits against it; which tool applies it is left to the duty holder. This page is an independent implementation of the HSE RR446 method with the NR/L2/OHS/003 figures loaded as the default profile.
What does NR/L2/OHS/003 actually set?
Two kinds of number. Hard limits, which are not to be rostered: a 12-hour duty, 12 hours between booking off and on, and no more than 13 duties in 14 days. Triggers, which require a documented exceedance assessment: hours in a rolling week, a fatigue index of 35 by day or 45 at night, a risk index of 1.6, and 14 hours door to door. Crossing a trigger does not stop the work; it starts the paperwork.
Why is the night trigger higher than the day trigger?
Because the index already penalises night work. Applying the daytime figure to nights would trip on almost every night duty, so the standard sets a higher figure for night-time working. Where a duty straddles both, the daytime figure is the stricter one and errs toward flagging.
Does a score under the trigger mean the roster conforms?
No. ORR's guidance asks for a work pattern to be assessed against its fatigue factors, with a bio-mathematical tool used alongside them and its limitations understood, and with feedback from the people working the pattern. RAIB's London Bridge report (January 2026) found that relying on the index alone to assess a base roster is not in line with that good practice. The index is one of three things, not the verdict.
Which of the standard's checks can a single duty show?
The duty length, the rest before it, the break, and the fatigue and risk indices for that duty with up to two prior duties feeding the cumulative component. The rolling-week hours, the consecutive-duty count and the door-to-door total need the whole roster, which is what the upload under the result is for.
Where does the amber band come from?
From RotaPulse, not from the standard. NR/L2/OHS/003 defines one fatigue index trigger per period of duty and no early-warning band. The amber figure is ours, set below the daytime trigger, so a planner sees a roster drifting toward an exceedance while there is still time to change it. It is labelled as ours wherever it appears.
One duty is a taster. The roster is the exceedance.
RotaPulse scores every duty on a roster against the NR/L2/OHS/003 profile, separates limits from triggers in plain English, proposes the smallest fix and produces a dated PDF for the SMS file. Free up to 10 workers.
Sources: Network Rail NR/L2/OHS/003 and the supply-chain procedures implementing it; ORR, Managing Rail Staff Fatigue (August 2024) and Good practice guidelines: fatigue factors (December 2021), Appendix D; RAIB report 09/2025, buffer stop collision at London Bridge (published January 2026); HSE Research Report RR446 (Spencer, Robertson and Folkard, 2006). RotaPulse is a TeZe Ltd product. This page is guidance, not a safety certification.