GTR (Govia Thameslink Railway)
Group Bourdon Test
Find every group of four. Miss nothing. — here is everything you need to know about the Group Bourdon Test before your GTR (Govia Thameslink Railway) OPC assessment.
Why the Group Bourdon matters for GTR (Govia Thameslink Railway) drivers
GTR (Govia Thameslink Railway) operates services across Southern England — Thameslink, Southern, Great Northern & Gatwick Express. Govia Thameslink Railway (GTR) is the UK's largest train operating company by passenger journeys, running Thameslink, Southern, Great Northern, and Gatwick Express services. All train driver applicants must pass the OPC psychometric test battery, regardless of which brand they'll be driving for — and the Group Bourdon Test is one of the key assessments that determines whether you will be shortlisted for the role.
Dense commuter schedules mean a driver completes multiple identical turns in a shift, each requiring the same standard of accuracy. There is no 'one easy run' to recover on. The Group Bourdon builds the systematic, consistent concentration that back-to-back commuter operation requires — the ability to maintain accuracy through repetition.
The Group Bourdon Test forms part of the OPC (Occupational Personality and Cognitive) battery used across all UK train operating companies, governed by RSSB standard RIS-3751-TOM. The format is identical at GTR (Govia Thameslink Railway) as at any other operator — but the stakes are specific to this application.
How the Group Bourdon works
Test format & scoring
Group Bourdon Test
Part of the GTR (Govia Thameslink Railway) OPC battery
A printed sheet of rows of dot groups (3, 4, or 5 dots each). Work systematically through every row and mark every group containing exactly four dots. Timed. Accuracy and coverage both contribute to your score.
What it measures: Sustained concentration and systematic accuracy — the ability to apply a simple rule repeatedly and correctly over a prolonged period without error rates increasing. One of the most direct measures of concentration stamina.
How to prepare
Preparation tips for GTR (Govia Thameslink Railway) candidates
Work left to right, never skip ahead
Irregular scanning is the primary source of omissions. Maintain a strict left-to-right rhythm across every row.
Mark and move — do not go back
Revisiting completed rows loses time and introduces doubt. Trust your first call.
Practise on paper, not on screen
The real test is pen and paper. Print practice sheets and sit them at a desk — the physical experience matters.
Track your error distribution
Errors in later rows indicate fatigue. Errors spread throughout indicate miscounting. Each pattern has a different fix.
GTR (Govia Thameslink Railway)-specific tip
After a practice run, immediately do a second one. The compounded concentration demand mirrors back-to-back commuter turns.
FAQ
Group Bourdon Test — common questions
Is the Group Bourdon done on paper or computer?
The traditional OPC version is a printed paper-and-pencil test administered in a group setting. Our practice generates a printable PDF sheet with a separate answer key.
How long does the Group Bourdon take?
The standard administration is typically 12–15 minutes. Speed and accuracy both contribute — a slow but highly accurate run scores better than a fast run with many errors.
What are the most common errors on the Group Bourdon?
Miscounting (marking a 3-dot or 5-dot group as four dots) and omission (skipping a genuine four-dot group). Both increase in the later rows as concentration fatigues.
Does the Group Bourdon appear at all UK operators?
It is part of the standardised OPC battery under RSSB RIS-3751-TOM and appears at most UK train operating companies, typically administered on paper before the computer-based tests.
Are the OPC tests the same for Thameslink, Southern, Great Northern and Gatwick Express?
Yes. All four brands are operated by GTR and use the same OPC psychometric battery for train driver selection, governed by the same RSSB standard (RIS-3751-TOM).
Ready to practise?
All GTR (Govia Thameslink Railway) OPC tests in one place — one payment, unlimited attempts.