Airport carries out a wide-ranging review of pedestrian slip risks
A busy regional airport has enjoyed considerable growth in traffic over recent years. This growth has meant higher pedestrian levels and the development of on site facilities to handle the increased passenger throughput. Airport management decided that it was an appropriate time to carry out a review of pedestrian slip risks on site. The review looked at risks to passengers, their own staff and those working for other organisations (such as the airlines and franchise holders).
The review involved considering a number of areas of the site where informed judgement suggested that there was at least the potential for slipping incidents. Microroughness measurements were taken of the floor surfaces in the areas under review. (Microroughness, in microns, is a significant factor influencing slip resistance of floors, especially in wet or contaminated conditions.) These measurements were considered together with other factors to provide a holistic picture and real-life assessment of slip risk.
Other slip risk factors incorporated into the overall assessment included
- Floor type and finish.
- Tasks and activities in the area under review.
- Who was using the area.
- Water or other likely floor contaminants.
- Staff footwear.
- Environmental influences in the area.
- Cleaning regimes.
A selection of the areas investigated, conditions found, conclusions drawn and responses made are summarised here.
Passenger check-in
The passenger check is an area where pedestrians (including young and old) are likely to be pushing, pulling or carrying loads, be rushing and possibly distracted. It has an epoxy painted concrete floor that is regularly cleaned with a mechanical scrubber dryer. The entrance is well protected from the elements and has extensive built in matting. Under normal conditions the check-in hall presented a low slip risk but should water be walked in on wet days or accidental spillages inside not be attended to there would be a significant risk.
Response
Objective is a clean & dry walking surface. Monitoring to see if walk-in water occurs, supplementary matting if necessary. Staff briefing on spillage spotting and the action to be taken.
Public concourse
Extending through a large part of the inside of the terminal the floor has a textured epoxy surface. It is subject to the same sorts of conditions and use as the check-in. Matting is not so good in the concourse entrances with some being ineffective as it is not placed to coincide with the direction that most pedestrians walk in after entering the door, walk-in water results. Weather canopies are provided at most entrances to limit water contamination. Floor surface roughness is moderate and will not cope with dirty or heavily contaminated conditions.
Response
Routine cleaning systems reviewed to control contamination potential and that the floor is fully dry immediately following cleaning.
Main revolving door entrance
The principal passenger entrance to the terminal building is a large powered revolving door. The outer half of the floor within the revolving door is covered with ceramic tiles. These tiles have very low microroughness, are exposed to rain and dirt and are located where encumbered pedestrians (young and old) are rushing, turning and distracted. Slip risk was identified as being high. The inner half of the floor within the circumference of the revolving door consists of coarse grit/dirt removal matting. Although this has some absorbent qualities its design (and heavily worn condition) render it of little use in preventing walk-in water being carried onto the adjacent concourse where control of contaminants is known to be important.
Response
Arrangements are being made to have the revolving door removed and pedestrian flow redirected to a better-controlled area. A decision made easier by the 'temperamental' nature of these particular powered doors.
'Duty Free' shop
High gloss ceramic decorative floor tiling with low microroughness. Originally thought to be likely to be a high-risk area but this proved not to be the case. The duty free shop is sited in the heart of the terminal building with no risk of walk-in water. Floor cleaning takes place at night when the shop is closed to the public. A no food & drink policy is enforced. There are no open products to contaminate the floor and bottle breakage responses and procedures are very well organised.
Response
Although the floor is glossy pedestrians never have anything other than a clean and dry floor to walk on. No action is needed.
Passenger toilets
Toilet facilities exist to serve the concourse in the 'land side' concourse area and the 'air side' departure lounge. All are cleaned to a high standard with a fully dry floor before being reopened to the public. However all toilet areas are likely to be subject to water contamination to the floor and will be used by people of varying physical capability. The toilet facilities 'air side' have textured epoxy resin flooring offering high microroughness that does not impair cleaning but does offer high slip resistance. The 'land side' facilities have gloss terrazzo floors - a beautiful finish visually but with very low microroughness and very slippery when wet.
Response
'Air side' - slip risk is low even in foreseeable wet circumstances. No action. 'Land side' - a real likelihood of slips occurring. There would be difficulties in bringing forward the floor replacement in advance of the next planned refit. Greater (labour costly) frequency and diligence of splash clean ups implemented and investigating etching treatment to the gloss terrazzo to improve surface microroughness and slip resistance in wet conditions.
Means of access to aircraft
Pedestrians boarding and alighting from aircraft can be expected to be carrying items, rushing and distracted. Some will be the young or elderly. Two main means of access exist: wheeled movable aircraft steps and powered 'umbilical' air-bridges.
The movable steps are kept outside and are exposed to the weather and a variety of potential contaminants to the walking surface but the profiled rubber treads to the steps still offer reasonable slip resistance.
Response
Periodic cleaning of the treads to control contamination and monitoring of the condition of the rubber surface for hardening or perishing brought on by exposure to the elements.
The air-bridges are floored with textured vinyl sheet for the most part and are cleaned to a high standard. Even with young and old, encumbered, rushing and distracted pedestrians the textured vinyl - protected as it is from foreseeable contamination of any significance - performs well. The last few feet of the air-bridges (where they dock with the aircraft and where the operative stands) are floored with metal chequerplate. Experience and experimentation suggest that the slip resistance of metal chequerplate in not a direct function of the raised profiling pattern but related more closely to the microroughness of the upper surface (the foot contact surface) of each profile cleat. Microroughness measurements and analysis of the other relevant conditions indicate there is little problem if the chequerplate is kept clean and dry but offered poor slip resistance if wet or contaminated. The most likely source of contamination is rainwater if the docking roller doors of the air-bridge are opened early in the docking process. This is of particular concern as, if the roller door is opened early, the operative is standing on a moving slippery surface close to an open drop to the tarmac below.
Response
Maintaining the high standards of floor cleaning and ensuring that strict operating disciplines are followed to prevent the opening the air-bridge docking end door until the last seconds of the docking manoeuvre.
Baggage handling hall
Where staff load luggage to and from trailers and conveyors in a handling bay opening onto the airport apron. The matt concrete surface has become ingrained with oily contamination and gets wet from pedestrians and baggage trucks from outside. Workers are manhandling loads and, although footwear standards are controlled, there is significant slip risk in this area. No real floor cleaning takes place.
Response
Restoring of the original roughness of the concrete floor surface with a one-off rigorous clean. Routine mop and detergent cleaning to introduced with occasional use of a mechanical scrubber to prevent ingraining of contaminants compromising the surface roughness and associated slip resistance.
Airport apron
Used as access and thoroughfares by aircrew, passengers moving to and from smaller aircraft and by airport staff. The concrete pathways are sufficiently textured that, even in wet and contaminated conditions and with additional problematic human and environmental factors, they provide excellent slip resistance. However, walkways and other important points on the apron are marked out with coloured lines marked out in a purpose made paint-like material. These lines exhibit very low microroughness and involve a high slip risk in the unavoidably wet and contaminated conditions. (Motorcyclists will be familiar with the loss of grip when crossing broken white lines to overtake.)
Response
As the apron markings have to be replaced or refreshed at intervals, that is the time when alternative, possibly textured, surface marking products are to be considered.
Airport fire station
The dock bays housing the airport's fire appliance are, not surprisingly, smartly kept. The floors of the appliance bays are light coloured paint on concrete and visibly clean and smooth - too smooth in fact, having very low surface microroughness. Although fire crews' footwear can be controlled to a high standard, a regularly wet environment with shiny painted floors, cleaned by hosing down, detergents from appliance cleaning and inevitably hurried, distracted users indicate a significant slip risk. Getting injured on the way to the appliance is not a good way to respond to an emergency.
Response
The uses of and activities in the fire station dock bay seem fixed and largely unavoidable but the floor paint is just starting to show its age in parts. To attempt to identify a floor paint or other surface treatment with the required combination of cleanliness, durability and microroughness.
Mobile work equipment and workplace vehicles
Metal chequerplate is in use on many items of workplace transport and mobile work equipment at the airport including fire appliances and working at height platforms. (See also 'means of access to aircraft - air-bridges', above.) It is generally placed where people stand on the equipment to work or on footholds used to climb up onto vehicles and equipment. The experiences of staff using these vehicles and equipment (usually outdoors and subject to water and other contamination) accord with the assessment made that metal chequerplate can be particularly slippery when wet. Ad-hoc attempts have been made to tackle this experienced slip risk by applying adhesive anti slip strips or sheets although this has been far from comprehensive.
Response
Each vehicle and piece of equipment to be inspected and assessed for retrofitting of adhesive anti slip coatings. 'Fitting as standard' of chequerplate is to be raised as an issue when specifying for or procuring new vehicle or equipment.