Space between a train car and the edge of the station platform
A Central line platform at Bank tube station, London, showing the 1-foot (30cm) gap between the train and the platform edge (delineated by a solid white line).
A platform gap (also known technically as the platform train interface or PTI in some countries) is the space between a train car (or other mass transit vehicle) and the edge of the station platform, often created by geometric constraints, historic legacies, or use of partially compatible equipment.[1]
Many high-quality bus rapid transit (BRT) systems also use high platforms at station stops to allow fast and efficient level boarding and alighting, but potentially leaving hazardous gaps between the platforms and the buses. Alignment setups such as Kassel curbs help to reduce platform gaps without requiring time-consuming manual alignment at each BRT station stop.
Definition and measurement
A platform gap has two component measurements:
vertical (difference between the platform height and train floor height)
horizontal (distance from the platform edge to the train step)[2]
Straight platforms
The ideal platform would be straight and align perfectly with a train or other large vehicle. Even in this case, a small gap between the conveyances and the platform is necessary to allow the vehicles to move freely without rubbing against the platform edge. In 2007, the Long Island Rail Road regarded an 8-inch (20cm) platform gap as typical on its non-curved platforms.[3]:12
In real-world situations, stations are often constrained by limited space, legacy designs, and track geometry or roadway layout. Stations may have to use a compromise design, with a platform curved in a way that will allow a vehicle or train to arrive and depart without mechanical interference, but which leaves unavoidable horizontal and possibly vertical gaps between the cars and the platform edge. These spaces are caused by the geometric gap between a curve (circular arc or otherwise) and the straight-line chord or tangent formed by a railcar or bus in proximity to a platform. These types of gaps are geometrically intrinsic, and cannot be eliminated as long as the platform is located on a curved or banked segment of track or guideway.
When passenger car doors are located only at the ends of each car (a common design for commuter rail and long-distance trains), platform access from a concave platform is preferred, since this brings the car ends in closest proximity to the platform edge. By contrast, a convex platform would leave the largest possible gaps between the car ends and the platform edge, making this design undesirable and thus rarely implemented.
An example of platforms designed for access from the concave side is at Lansdowne station in Boston, where side platforms for both the inbound and outbound directions are located to reduce platform gaps to commuter rail trains of the Framingham/Worcester Line. Concave and convex gaps also exist in several MTR stations in Hong Kong, particularly on the East Rail line, which was built on the historic Kowloon–Canton Railway line.
Gap fillers
This German regional train (DB class 442) has door-mounted gap fillers
Mechanical platform edge extensions known as platform gap fillers may be used to bridge the gap between platform and vehicle. These stopgaps require careful alignment of the vehicle upon arrival, and careful synchronization to avoid serious damage caused by departure of the vehicle before the extenders are fully retracted. They increase station dwell time, and introduce safety and maintenance concerns of their own.
Alternatively, the gap fillers may be mounted on the train, and linked to the door operating mechanism. They may be found on modern trainsets, like various versions of the Stadler GTW.[failed verification] Train-mounted gap fillers eliminate the need for careful alignment and, as the driver only gets the signal that the doors have closed when the fillers have fully retracted, require no special synchronization on departure. Moving all active components of the system to the train instead of the platform allows maintenance to be performed in a shop, rather than in the field. Singapore has committed to specifying its newer trains with gap fillers, to reduce the incidence of platform gap accidents in its crowded stations.[4]
On the Berlin U-Bahn, which has two different loading gauges (Kleinprofil on U1-U4 and Großprofil on U5-U9), so-called Blumenbretter ("flower boards") bridging the platform gap were attached to Kleinprofil trains that ran on Großprofil lines at various times of rolling stock shortage.[5][6][7]
Equipment compatibility
In some rail systems, significant platform gaps may also occur (both horizontally and vertically) because of equipment and platforms designed to different and somewhat incompatible height and width standards. This situation may occur especially when previously separate rail systems are consolidated, or start to interoperate, thus allowing equipment to be moved onto tracks where it had not been used before.
In 2007, public testimony by the acting president of the Long Island Rail Road cited the need to interoperate with freight service and other passenger services such as New Jersey Transit and Amtrak, in addition to its own diverse rolling stock, as complicating and slowing efforts to deal with platform gap hazards.[3]:6–8
Other contributing factors
Other variables that can increase platform gaps include rail wear, wheel wear, condition of the railcar suspension, and passenger load.[3]:16 A further complication is super-elevation, deliberate tilting of the railbed to allow faster travel around curves. This factor is especially relevant on systems where some express trains (such as long-distance Amtrak trains) operate non-stop through local stations located on curves.[3]:15 Higher pass-through speeds also increase railcar sway, requiring even larger physical clearances to avoid platform strikes.
Specifications and limits
The severe concave platform curvature at 14th Street–Union Square requires gap fillers at regular intervals
In the US, the Americans with Disabilities Act requires that platforms be “readily accessible to and usable by individuals with disabilities, including individuals who use wheelchairs (49 CFR Part 37, Appendix A, 10.3.1 (9))”. However, this rule only applies to new construction or major renovations of stations. A 2009 report to the New Jersey Department of Transportation (NJDOT) observes that ADA rules specify that "At stations with high level platforms, there may be a gap of no more than 3” horizontal and 5/8" vertical between platform edge and entrance to the rail car. However, currently no passenger rail system in the U.S. has been able to achieve this without the use of manually operated 'bridge plates'.”[8]:2
As of 2007[update], the US Federal Railway Administration recommended platform gap maximum limits of 7–10 inches (18–25cm), and 10–13 inches (25–33cm) on curves.[3]:19
Mitigation
Physical measures to reduce platform gaps may include realigning trackbeds, realigning platform slabs, and extending platform edges with wooden boards.[3]:22–24 Operational measures may include "zoning off" some railcars (not opening certain doors at problematic stations), relocating where trains stop along a lengthy platform, and temporarily deploying "platform conductor" personnel to assist passengers.[3]:25–27
On systems where the floor level of the vehicle and the platform height closely match, an extendible platform can be installed below the doors of the vehicle, to deploy when the doors are opened. This significantly decreases the gap and thus the risks when boarding and alighting vehicles at stations or stops. This method is used by the German BR423EMU's and its derivatives, including the Dutch variant SLT.
A public awareness campaign may be used, employing visually distinct platform edge markings, posters, signs, public safety announcements, and web videos to increase safety awareness.[3]:28–34 The MTA Long Island Rail Road website lists some precautions passengers should observe regarding platform gaps.[9]
An article in The Guardian conceded that some passengers who have fallen into platform gaps were drunk at the time, but pointed out other incidents when victims did not have that impairment. The writer complained specifically about gaps that measured from 46 to 51 centimetres (18 to 20in) which posed safety threats to children and the elderly, and called for modification of dangerous platforms.[10]
Criticism
In 1865 the Franklin Institute reported on 'the frequent loss of life that occurred on station platforms' and stated that 'platforms should be built up to the level of the flooring of the carriages, and that a dangerous space between the platform and the carriages ought not to exist'.[2]
A 2009 American report identified platform gap injury risk factors, including "mobility, being elderly, having disabilities (visual impairment), being accompanied by small children or incidents occurring to small children, behavior of other passengers such as pushing or jostling, carry luggage and other articles, alcohol, degraded platform conditions such as crowding, wet platforms or uneven platforms, and stepping distances".[8]:5
In 2023, British transport systems lecturer and co-founder of UK-based Campaign for Level Boarding Gareth Dennis said achieving level boarding "should be a core objective" for any operators and that it is "not acceptable" for passengers to have to worry whether there will be an attendant with a ramp at their destination.[2] He criticised London's Crossrail project's "poor decision making" which set new inner-city station floor heights on the Elizabeth line at train floor level, while outer suburban platforms remained at their pre-existing height, about 200mm lower: "This brand-new railway has cornered itself into perpetually offering an inaccessible service."[2]
In 2014, a news service in Mumbai, India reported several serious platform gap mutilation incidents and a death within a few months, mostly attributed to crowded conditions.[12] In 2015, Singapore had at least two platform gap incidents which were eventually resolved, but caused significant disruptions in rush-hour service.[4]
In 2014 in Perth, Australia, an accident occurred when a man fell between the platform and the train, and could not release his leg because the gap was too small. Other passengers "rocked" the carriage sideways to increase the gap, allowing the victim to escape.[13]
In 2022 in Duvvada, India, a girl who was standing at the door for alighting was knocked down by the door due to a sudden jerk, and she fell into the gap between coach and the platform, In spite of immediate rescue efforts launched by authorities to free her, it took almost an hour to cut the platform and rush her to the hospital. Injuries to her internal organs led to her death within a day.[14]
See also
Mind the gap– Warning to train passengers boarding and disembarking
Platform gap filler– Movable platform edge extensions at subway or railway stations
A railway platform is an area alongside a railway track providing convenient access to trains. Almost all stations have some form of platform, with larger stations having multiple platforms.
A conductor or guard is a train crew member responsible for operational and safety duties that do not involve actual operation of the train/locomotive. The conductor title is most common in North American railway operations, but the role is common worldwide under various job titles. In Commonwealth English, a conductor is also known as guard or train manager.
"Mind the gap" or sometimes "watch the gap" is an audible or visual warning phrase issued to rail passengers to take caution while crossing the horizontal, and in some cases vertical, spatial gap between the train doorway and the station platform edge.
A bilevel car or double-decker coach is a type of rail car that has two levels of passenger accommodation as opposed to one, increasing passenger capacity.
In railroad structures and rail terminology, a wye or triangular junction is a triangular joining arrangement of three rail lines with a railroad switch at each corner connecting to the incoming lines. A turning wye is a specific case.
A loading gauge is a diagram or physical structure that defines the maximum height and width dimensions in railway vehicles and their loads. Their purpose is to ensure that rail vehicles can pass safely through tunnels and under bridges, and keep clear of platforms, trackside buildings and structures. Classification systems vary between different countries, and gauges may vary across a network, even if the track gauge is uniform.
The New York Transit Museum is a museum that displays historical artifacts of the New York City Subway, bus, and commuter rail systems in the greater New York City metropolitan region. The main museum is located in the decommissioned Court Street subway station in Downtown Brooklyn and Brooklyn Heights in the New York City borough of Brooklyn. There is a smaller satellite Museum Annex in Grand Central Terminal in Midtown Manhattan. The museum is a self-supporting division of the Metropolitan Transportation Authority.
Lo Wu is the northern terminus of the East Rail line of Hong Kong, located in Lo Wu within the Closed Area on Hong Kong's northern frontier. The station serves as a primary checkpoint for rail passengers between Hong Kong and mainland China and vice versa, rather than serving a specific area. It is also the northernmost railway station in Hong Kong.
LeShuttle is a railway shuttle service between Calais in France and Folkestone in United Kingdom. It conveys road vehicles and passengers by rail through the Channel Tunnel. Freight vehicles are carried in separate shuttle trains hauled by the same locomotives, that also contain a passenger carriage, known as the Club Car.
A balloon loop, turning loop, or reversing loop allows a rail vehicle or train to reverse direction without having to shunt or stop. Balloon loops can be useful for passenger trains and unit freight trains.
Platform screen doors (PSDs), also known as platform edge doors (PEDs), are used at some train, rapid transit and people mover stations to separate the platform from train tracks, as well as on some bus rapid transit, tram and light rail systems. Primarily used for passenger safety, they are a relatively new addition to many metro systems around the world, some having been retrofitted to established systems. They are widely used in newer Asian and European metro systems, and Latin American bus rapid transit systems.
A structure gauge, also called the minimum structure outline, is a diagram or physical structure that sets limits to the extent that bridges, tunnels and other infrastructure can encroach on rail vehicles. It specifies the height and width of station platforms, tunnels and bridges, and the width of the doors that allow access to a warehouse from a rail siding. Specifications may include the minimum distance from rail vehicles to railway platforms, buildings, lineside electrical equipment cabinets, signalling equipment, third rails or supports for overhead lines.
Platform gap fillers are movable platform edge extensions at subway or railway stations where the curvature of the platform creates a significant gap between the platform and subway or train car door.
Syosset station is a commuter rail station on the Long Island Rail Road's Port Jefferson Branch in Syosset, New York. It is located at Jackson Avenue and Underhill Boulevard, south of New York State Route 25A, but north of Jericho Turnpike and the Long Island Expressway. Syosset's downtown was built around the station. There are no public transportation connections at the station, but taxi service is available.
Railway platform height is the built height – above top of rail (ATR) – of passenger platforms at stations. A connected term is train floor height, which refers to the ATR height of the floor of rail vehicles. Worldwide, there are many, frequently incompatible, standards for platform heights and train floor heights. Where raised platforms are in use, train widths must also be compatible, in order to avoid both large gaps between platforms and trains and mechanical interference liable to cause equipment damage.
In transportation, dwell time or terminal dwell time refers to the time a vehicle such as a public transit bus or train spends at a scheduled stop without moving. Typically, this time is spent boarding or deboarding passengers and baggage, but it may also be spent waiting for traffic ahead to clear, trying to merge into parallel traffic, or idling time in order to get back on schedule. Dwell time is one common measure of efficiency in public transport, with shorter dwell times being universally desirable.
The Tyne and Wear Metrocars are a fleet of light rail vehicles manufactured by Metro-Cammell for the Tyne and Wear Metro in North East England between 1978 and 1981. For operation on Network Rail controlled tracks between Pelaw Junction and Sunderland, they are designated on TOPS as the Class 599. Most were refurbished between 2010 and 2015 by Wabtec Rail at Doncaster Works and are scheduled to be replaced by Class 555 rolling stock from 2024.
High-floor describes the interior flooring of commuter vehicles primarily used in public transport such as trains, light rail cars and other rail vehicles, along with buses and trolleybuses. Interior floor height is generally measured above the street surface or above the top of the rail. High-floor designs usually result from packaging requirements: mechanical items such as axles, motors, crankshafts, and/or transmissions, or luggage storage spaces are traditionally placed under the interior floor of these vehicles. The term is used in contrast with low-floor designs, which offer a decreased floor and entry height above the street surface. Since low-floor designs generally were developed after high-floor vehicles, the older high-floor design is sometimes also known as conventional or the “traditional” design.
The Siemens S200 is a high-floor light rail vehicle (LRV) manufactured by Siemens Mobility in Florin, California. The S200 succeeds the SD-100, SD-160, SD-400 and SD-460 as the high-floor light rail vehicle for the North American market and is being manufactured and marketed alongside the low-floor Siemens S700.
A bridge plate, or bridgeplate, is a mechanical, movable form of wheelchair ramp that is used on some low-floor light rail vehicles (LRVs) to provide for wheelchair access. The bridge plate extends from the vehicle to the platform, which must be raised to close to the level of the floor of the vehicle so that the wheelchair need not travel over an excessively steep ramp. Some low-floor buses also use bridge plates to provide for wheelchair access, but many low-floor buses instead use a ramp that normally serves as part of the floor but can be flipped out through the door onto the curb or street; in this case the ramp is long enough that it can serve as a true wheelchair ramp rather than a bridge without being excessively steep.
References
↑ The Engineering Handbook of Smart Technology for Aging, Disability and Independence, Page 563
1 2 3 4 Gareth Dennis, 'Time to "mind the gap" once and for all' in Railway Gazette International May 2023 p40
1 2 Daniel, Janice R.; Rotter, Naomi G. (2009). "FHWA-NJ-2009-009"(PDF). Customer Behavior Relative to Gap Between Platform and Train. NJDOT and FHA. Retrieved 26 May 2014.
↑ "Watch the Gap". MTA.info. Metropolitan Transportation Authority (NYC). Retrieved 26 May 2014.
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