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.
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.[2]: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.[3]
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.[4][5][6]
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.[2]: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.[2]: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.[2]: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'.”[7]: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.[2]:19
Mitigation
Physical measures to reduce platform gaps may include realigning trackbeds, realigning platform slabs, and extending platform edges with wooden boards.[2]: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.[2]: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.[2]:28–34 The MTA Long Island Rail Road website lists some precautions passengers should observe regarding platform gaps.[8]
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.[9]
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".[7]:5
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.[11] In 2015, Singapore had at least two platform gap incidents which were eventually resolved, but caused significant disruptions in rush-hour service.[3]
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.[12]
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.[13]
See also
Mind the gap– Warning to train passengers boarding and disembarking
Platform gap filler– Movable platform edge extensions at subway or railway stations
The Long Island Rail Road, often abbreviated as the LIRR, is a railroad in the southeastern part of the U.S. state of New York, stretching from Manhattan to the eastern tip of Suffolk County on Long Island. The railroad currently operates a public commuter rail service, with its freight operations contracted to the New York and Atlantic Railway. With an average weekday ridership of 354,800 passengers in 2016, it is the busiest commuter railroad in North America. It is also one of the world's few commuter systems that runs 24/7 year-round. It is publicly owned by the Metropolitan Transportation Authority, which refers to it as MTA Long Island Rail Road. In 2023, the system had a ridership of 75,186,900, or about 253,800 per weekday as of the fourth quarter of 2023.
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.
"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.
The East Rail line is one of the ten lines that form MTR, the mass transit system in Hong Kong. The railway line starts at Lo Wu or Lok Ma Chau, both of which are boundary crossing points into Shenzhen and joins in the north at Sheung Shui and ends at Admiralty station on Hong Kong Island. At approximately 46 km (29 mi), the line is the second longest line within the network, behind the Tuen Ma line. The line's colour is light blue.
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.
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.
The rolling stock on the Berlin U-Bahn are the main types of cars for the underground railway (subway). They are split into two general categories: Kleinprofil and Großprofil lines. The names refer to the size of the train's coaches. Großprofil coaches have a width of 2.65 m and a height of 3.4 m, and Kleinprofil coaches are only 2.3 m wide and 3.1 m high. Therefore, the trains have to operate on separate networks.
Broadway is a station on the Long Island Rail Road's Port Washington Branch in the East Flushing and Broadway neighborhoods of Queens, New York City. The station is east of a rail overpass at the intersection of 162nd Street and Northern Boulevard. This station contains ramps that comply with the Americans with Disabilities Act (ADA), making it fully accessible.
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 is a station on the Long Island Rail Road's Port Jefferson Branch located in Syosset, New York, 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, 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 C3 is a bi-level coach railroad car built by Kawasaki. Ordered by the Metropolitan Transportation Authority for use on the Long Island Rail Road (LIRR), the cars began to enter revenue service in 1997. The rail cars are pulled and pushed by EMD DE30AC and DM30AC dual-mode locomotives. The C3 cars are powered by 480 V AC head-end power supplied from the locomotive.
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.
Class E was a series of Großprofil multiple units of Berliner Verkehrsbetriebe (BVG) which was exclusively used on East Berlin line E, today line U5 of the Berlin U-Bahn. Except for the two prototypes, all vehicles were built using parts of retired S-Bahn vehicles, namely the bogies and parts of the electrical equipment.
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 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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