Pendulum Slider Selection — 96 vs 55 vs 57

The three sliders

Slider	Hardness (IRHD)	Compound	Pedestrian simulated
Slider 96	96	Four-S rubber	Standard shoe heel
Slider 55	55	TRL rubber	Bare wet skin / smooth sole
Slider 57	57	Simulated soft sole	Soft footwear, sock, slipper

The numerical designation refers to the rubber's hardness on the International Rubber Hardness Degrees scale.

Slider 96 — the standard for shod environments

Slider 96 is the default for almost all UK pendulum testing because almost all UK pedestrian environments are shod. The rubber compound is harder, simulating the rubber heel of a normal shoe striking the floor. PTV results from Slider 96 testing are the values referenced by HSE bands, BS 8204, NHS specifications, and almost all insurer schedules.

If a specification simply says 'PTV' without specifying a slider, it almost always means Slider 96.

Slider 55 — for barefoot wet environments

Slider 55 is the softer compound used in environments where pedestrians are barefoot on wet surfaces — pool surrounds, communal showers, hydrotherapy areas, beach club terraces. Bare wet skin grips a wet surface differently to a rubber heel; Slider 96 testing in these environments produces misleadingly conservative results that do not represent the actual barefoot-and-wet pedestrian.

Slider 55 is paired with the BS EN 16165 Annex A barefoot ramp test for full assessment of barefoot environments — pendulum data from Slider 55 is the in-situ measurement, ramp data from Annex A is the product-level rating.

Slider 57 — for soft footwear and sock environments

Slider 57 is a less commonly specified slider, used for soft-sole, sock or slipper environments — care homes where residents are routinely in slippers, soft-play centres where children are in socks, dance studios where movement is in soft shoes. The hardness sits between Slider 96 and Slider 55, simulating the friction characteristics of a soft-sole footwear contact.

Why mis-selection invalidates the test

A pool surround tested with Slider 96 will produce PTV results that may meet the 36+ threshold — and an inexperienced reviewer might conclude the surface is compliant. But the surface as tested is not the surface as walked on. The barefoot pedestrian on the same surface will experience materially different friction, and the test result is therefore not evidence about that pedestrian's slip risk.

Conversely, a retail entrance tested with Slider 55 will produce PTV results that look much lower than the actual shod pedestrian experiences — also misleading.

Mixed environments

Some environments require both sliders because they are walked on in both modes:

• Hotel pool changing rooms — shod entry, barefoot transit to pool, shod exit
• Spa entrance halls — guests transition shoe-to-slipper
• Care home wet rooms — staff in shoes, residents potentially in slippers or barefoot

Best practice in these cases is dual-slider testing, with separate PTV values reported for each slider.

Slider conditioning between tests

Whichever slider is used, the slider edge must be conditioned to standard roughness before each set of recorded swings — typically by abrading on prescribed lapping paper. Insufficient or incorrect conditioning produces unreliable results regardless of which slider is fitted. The conditioning protocol is part of the BS EN 16165 Annex C method and is one of the items UKAS assessors verify.