BS EN 16165 Annex C — The Pendulum Test Method

How BS EN 16165 came about

The European Committee for Standardization (CEN) consolidated four existing national slip-test standards into a single European standard, BS EN 16165:2021, published in December 2021 and adopted across the UK in February 2022. The four methods previously published separately are now annexes of the single standard:

• Annex A — barefoot ramp (replaces DIN 51097)
• Annex B — shod ramp (replaces DIN 51130)
• Annex C — pendulum test (replaces BS 7976-2)
• Annex D — tribometer test

The UK National Foreword

The UK National Foreword to BS EN 16165 contains a significant statement: the pendulum test (Annex C) is considered the only one of the four methods that should be relied on to correctly assess pedestrian slip risk in wet conditions. This reflects the UK's four decades of forensic experience with the pendulum and aligns with HSE practice.

For UK in-situ slip risk assessment, in other words, Annex C is the method.

Equipment specified by Annex C

The Annex C pendulum is the TRL-pattern (Transport Research Laboratory) pendulum tester, also known as the British Pendulum, the Stanley pendulum, or the Munro pendulum (different manufacturers produce instruments to the same specification). The instrument comprises:

• A weighted arm pivoted on a horizontal axis
• A rubber slider mounted at the foot of the arm
• A graduated scale indicating residual swing
• A levelling and height-adjustment system to set the slider correctly above the test surface

Slider types — 96, 55, 57

Three sliders are specified for different conditions:

Slider	Hardness	Simulates	Typical use
Slider 96	Four-S rubber, 96 IRHD	Standard shoe heel	Shod environments — most testing
Slider 55	TRL rubber, 55 IRHD	Bare wet skin	Pool surrounds, barefoot wet zones
Slider 57	Simulated soft sole	Soft footwear	Sock/slipper environments

Detail on slider selection in our dedicated slider guide.

Calibration requirements

Annex C specifies pre-test calibration procedures including: friction-disc check (a reference disc producing a known PTV reading), slider conditioning (the slider edge must be conditioned to a specific roughness before testing), and instrument verification (level, slider sweep distance, slider release height). Each of these has its own sub-procedure with tolerances.

Detail on calibration in our calibration guide.

Test procedure

The standardised procedure for each test point:

1. Surface preparation — remove loose contamination, wet the surface for wet testing
2. Slider conditioning — abrade the slider edge to standard roughness on prescribed paper
3. Practice swings — release the pendulum to allow the slider to settle into the surface
4. Recorded swings — typically five swings per direction, results averaged
5. Re-conditioning between sets — the slider edge is conditioned again before the next set
6. Three directions of test — typically front-back, left-right, and a third diagonal

Reporting requirements

Annex C specifies what a compliant report must contain: identification of the surface tested, the slider used, the conditions (wet/dry, contaminant if not water), the calibration record, the individual swing results per direction, and the calculated mean PTV per location. UKAS-accredited reports go further, including methodology declarations, equipment serial numbers, traceability statements and the technical signatory.

If your specification still references BS 7976-2

The pendulum test you receive under BS EN 16165 Annex C is, in technical terms, the same test as under BS 7976-2. Specifications and contracts that still reference BS 7976-2 by name are typically satisfied by Annex C testing. New specifications should reference BS EN 16165:2021 directly.