A low-floor tram is a tram that has no stairsteps between one or more entrances and part or all of the passenger cabin. The low-floor design improves the accessibility of the tram for the public, and also may provide larger windows and more airspace.
An accessible platform-level floor in a tram can be achieved either by using a high-floor vehicle serving high-platform tram stops, or with a true low-floor vehicle interfacing with curb level stops.
Currently both types are in use, depending on the station platform infrastructure in existing rail systems. Some systems may make use of former railway alignments where use of existing high platforms is desirable, while others, particularly new systems, may not have the space to site high-level stops in urban centres.
Trams traditionally had high floors, and these designs evolved into the tram with a low-floor centre section. Examples of this design are Amsterdam 11g/12g-trams and the Kusttrams in Belgium.
The most common design of 100% low floor vehicles uses short carbody sections for the wheels and longer suspended sections. Examples of this are the Citadis and Combino. A similar, but somewhat older technique is one that has been developed by MAN. In 1990, it was the first 100% low floor tram. These trams are found in ten German cities (such as Bremen and Munich) and in the Swedish city Norrköping. In many other German cities there are trams with low floor between the outer bogies and single axle bogies under the centre section.
"Light rail" type vehicles frequently have a similar configuration but with a centre bogie designed to accommodate a low floor situated under a short centre section. A more radical approach has been adopted for the City Class LRV (Citytram), where the main low floor section is only 300 mm above the rail. The low floor runs right through the articulation of both the 29 m long and 38 m Super Citytram version. In both, the corridor through the articulation is wide enough for seated passengers and a wheelchair to pass through. The City Class has been designed to turn on 15 m radius curves and to climb 10% gradients.
In Austria, the Porsche designed Ultra Low Floor (ULF) Trams can "kneel" at the curbside, reducing the height from the road to only 180 mm.
Some public transport companies have both low floor and high floor trams. They report that low floor trams have 15% higher maintenance costs for the rolling stock, and 20% higher maintenance costs for the infrastructure on average. Among the problems observed is that the missing bogies result in a higher level of wear and tear.
Many low floor trams have fixed bogies which increase track wear and tear, while decreasing the speed at which a tram can drive through a curve (usually 4–15 km/h in 20 m radius curve). The Škoda ForCity and the newest Alstom Citadis X04 try to counter the effect with low floor pivoting bogies while maintaining 100% low floor design. Prior to the new design, pivoting bogies could only be used under high floors, hence such trams could only be part low-floor, with high-floor sections over the pivoting bogies.
The idea of a low-floor tram dates back to the early 20th century when a number of trolley systems began experimenting with various "stepless" designs. Perhaps the most notable is the Hedley-Doyle Stepless car introduced in 1912 for use on Broadway in Manhattan. A number of other cities also purchased Hedley-Doyle Stepless trams after seeing their success in Manhattan. Since these cars had a unique appearance compared to any other trams running at the time, they earned a number of nicknames, including hobble skirt cars, public welfare cars, and sow bellies.
To put things into perspective, here are some typical floor heights for public transport vehicles, old and new:
Ultra Low Floor tram — 180 mm (7 inches)
Low-floor tram — 300 mm to 350 mm (11.8 to 13.78 inches)
High-floor tram — more than 600 mm (23.62 inches)
Heavy rail rapid transit — 800 mm (31.5 inches) to 1200 mm (47.25 inches)
North American inter-city rail passenger cars — 1350 mm (51 inches)
Belkamunmash
AKSM-743 - Third Generation tram on Minsk tramway
AKSM-843 - Fourth generation tram on Minsk tramway
Bombardier Transportation (are subtypes and more)
A32 Flexity Swift
Citytram
Cobra
CR4000 Flexity Swift
GT8-100D/2S-M
ET 2010 Flexity Swift (Tram-train)
E-class Melbourne tram Flexity Swift
Flexity 2
Flexity 2 (version for Blackpool)
Flexity Berlin (Incentro family)
Flexity Classic
Flexity Freedom
Flexity Link
Flexity Outlook Eurotram
Flexity Outlook Cityrunner
Flexity Outlook Olympic Line
Flexity Outlook (version for Toronto)
GT8-100D/2S-M
HF6 Flexity Swift (not low-floor, but due to the high platform is wheelchair access)
Incentro
Incentro AT6/5 (version for Nottingham)
K4000 Flexity Swift
K4500 Flexity Swift
K5000 Flexity Swift (not low-floor, but due to the high platform is wheelchair access)
K5200 Flexity Swift (not low-floor, but due to the high platform is wheelchair access)
M5000 Flexity Swift (not low-floor, but due to the high platform is wheelchair access)
Traintram Flexity Swift
Type 1 LVR Flexity Swift
T2000
Variotram
CROTRAM
TMK 2200 (NT 2200)
TMK 2200 K
TMK 2300
ČKD Tatra
K3R-N (reconstruction with low-floor middle article)
K3R-NT (reconstruction with low-floor middle article)
KT8D5N (reconstruction with low-floor middle article)
KT8D5R.N1 (reconstruction with low-floor middle article)
KT8D5R.N2 (reconstruction with low-floor middle article)
KT8D5R.N2P (reconstruction with low-floor middle article)
KTNF6 (reconstruction with low-floor middle article)
KTNF8 (reconstruction with low-floor middle article)
RT6N1
RT6N2
RT6S
Satra III (reconstruction with low-floor middle article)
Aliance TW Team
Tatra T3R.PLF (nicknamed "wana" (in Czech language bath) - newly built with low-floor middle section)
Tatra T3R.SLF ("wana")
VarioLF ("wana")
VarioLF plus ("wana")
VarioLF plus/o ("wana")
VarioLF2
VarioLF2 plus
VarioLF2/2 IN
VarioLF3
VarioLF3/2
EVO1
EVO2
VV60LF (tow tramcar)
Škoda Transportation
03T Astra/Anitra/Elektra
05T Vektra
06T Elektra
10T Elektra
13T Elektra
14T Elektra
15T ForCity Alfa
16T Elektra
19T Elektra
26T ForCity Classic
27T
28T ForCity Classic
29T ForCity Plus
30T ForCity Plus
Artic ForCity Smart
Inekon Trams
01 Trio
04 Superior
11 Pento
12 Trio
Alstom
ATM Class 6000
Citadis 100
Citadis 202 (on Melbourne tramway locally designated C-class)
Citadis 301
Citadis 301 CIS numbers: 71-801.
Citadis 302 (on Melbourne tramway locally designated C2-class)
Citadis 401
Citadis 402
Citadis 403
Citadis 502
Citadis X-04 (204, 304, 404)
Citadis X-05 (205, 305, 405)
Regio-Citadis
Citadis Dualis
Citadis Compact
Citadis Spirit
Tatra KTNF8 in Gera
Tramway Français Standard (TFS)-1 (low-floor added at a later date)
TFS-2
Translohr vehicles
TW 2000 (not low-floor, but due to the high platform is wheelchair access)
Allgemeine Elektricitäts-Gesellschaft AG (AEG)
ATAC Class 9000
DÜWAG
Düwag-Vevey Be 4/6
Düwag-Vevey Be 4/8
GT6-70D/N
GT8-100C/2S
GT8-100D/2S-M
GT8N (reconstruction with low-floor middle article)
GT8Z (reconstruction with 73% low-floor)
GT10 NC-DU (reconstruction with low-floor middle article)
MGT6D
M8C (not low-floor, but due to the high platform is wheelchair access)
M8C-NF (reconstruction with low-floor middle article)
MGT6D
Moderus Beta MF 01, MF 13, MF 14 AC BD, MF 18 (reconstruction with low-floor middle article)
M97 (reconstruction with low-floor middle article)
N8C (not low-floor, but due to the high platform is wheelchair access)
Stadtbahnwagen B (not low-floor, but due to the high platform is wheelchair access)
Supertram
TW 6000 (not low-floor, but due to the high platform is wheelchair access)
U2 (not low-floor, but due to the high platform is wheelchair access)
U3 (not low-floor, but due to the high platform is wheelchair access)
U4 (not low-floor, but due to the high platform is wheelchair access)
6MGT
8MGT
MAN SE
N8C (not low-floor, but due to the high platform is wheelchair access)
N8S-NF (reconstruction with low-floor middle article)
Siemens
Avenio (on Munich tramway locally designated class T1)
Combino (on Melbourne tramway locally designated D1-class and D2-class)
Combino Plus (also known as Combino Supra or Combino MkII)
GT6-70D/N
GT8-70D/N
GT8-100D/2S-M
N8C (not low-floor, but due to the high platform is wheelchair access)
Supertram
S70
SD-160 in platform level version (not low-floor, but due to the high platform is wheelchair access)
S200 (not low-floor, but due to the high platform is wheelchair access)
SD-400 (not low-floor, but due to the high platform is wheelchair access)
SD-460 (not low-floor, but due to the high platform is wheelchair access)
Stadtbahnwagen B (not low-floor, but due to the high platform is wheelchair access)
TW 2000 (not low-floor, but due to the high platform is wheelchair access)
Ultra Low Floor (ULF) in Vienna
U2 (not low-floor, but due to the high platform is wheelchair access)
U3 (not low-floor, but due to the high platform is wheelchair access)
U4 (not low-floor, but due to the high platform is wheelchair access)
ADtranz
Eurotram (on Milan tramway locally designated as Class 7000)
GTxN/M/S (on Munich tramway locally designated classes R2 and R3)
GT6-70D/N
GT8-70D/N
GT8-100D/2S-M
N8C (not low-floor, but due to the high platform is wheelchair access)
Variobahn
Vossloh Kiepe
GTZ8-B Vamos (not low-floor, but due to the high platform is wheelchair access)
N8C (not low-floor, but due to the high platform is wheelchair access)
Stadtbahnwagen B
AnsaldoBreda
ATM Class 5000
ATM Class 7100 (family Sirio)
ATM Class 7500 (family Sirio)
ATM Class 7600 (family Sirio)
M32 trams on Gothenburg tramway (family Sirio)
TEB serie 001-014 on Bergamo–Albino light rail
SL95
T-68 (not low-floor, but due to the high platform is wheelchair access)
T-68A (not low-floor, but due to the high platform is wheelchair access)
T-69
Fiat Ferroviaria
ATM Class 5000
ATM Class 6000
ATAC Class 9100
ATAC Class 9200
Società Costruzioni Industriali Milano (Socimi)
ATAC Class 9000
Eurotram (on Milan tramway locally designated as Class 7000)
Alna Sharyo
Little Dancer Type A
Little Dancer Type C
Little Dancer Type L
Little Dancer Type S
Little Dancer Type U
Little Dancer Type Ua
Kinki Sharyo
Green Mover Max
Kinki Sharyo SLRV
Poland
Konstal
Konstal 112N
Konstal 114Na
Konstal 116N/116Na
Konstal NGd99
Konstal 116Nd
Modertrans
Moderus Beta MF 01, MF 13, MF 14 AC BD, MF 18 (reconstruction with low-floor middle article)
Moderus Beta MF 02 AC, MF 15 AC, MF 16 AC BD, MF 19 AC (reconstruction with low-floor middle article)
PESA
120N Tramicus
120Na Swing
121N Tramicus
121Na Swing
122N Tramicus
122Na Swing
128N Jazz
128NG Jazz
134N Jazz
2010N Twist
2012N Twist Step
2014N Twist Krakowiak
71-414 Twist Fokstrot
Protram
Protram 204 WrAs
Protram 205 WrAs
Protram 206 WrAs - In project phase
Solaris Bus & Coach
Solaris Tramino
Electrontrans
Electron T3L44 (experimental)
Electron T5L64 (experimental)
Electron T5B65
Tatra-Yug
K-1M6 (experimental)
K-1M8
K-1M
Construcciones y Auxiliar de Ferrocarriles (CAF)
Urbos 1
Urbos 2
Urbos 3 - version Urbos 70
Urbos 3 - version Urbos 100
Urbos 3 - version Urbos AXL
Urbos 3 - version Urbos TT
Urbos 3 - version Urbos LRV
Vossloh España
British Rail Class 399 Citylink
NET 2012
Switzerland
ABB Group
GT8-100C/2S (not low-floor, but due to the high platform is wheelchair access)
Tram 2000 Be 4/8 (low-floor middle article)
Variobahn
Stadler Rail
Tango (Model Bochum)
Tango (Model Basel)
Variobahn (on Munich tramway locally designated class S)
PTMZ (Petěrburgskij tramvajno-mechaničeskij zavod)
LVS-2005
LVS-2008
LVS-2009
UKVZ (Usť-Katavskij vagonstrojitělnyj zavod imeni Sergeje Mironoviče Kirova)
KTM-23 (71-623)
KTM-24 (71-624)
KTM-25 (71-625)
KTM-30 (71-630)
KTM-31 (71-631)
71-911 City Star
71-931 Vityaz
AKSM 843 (BKM 843)
Siemens S70Konstal 116NAvanto (aka. Siemens S70)
BKM 85300M
DL6WA, mark Dalianren (meaning "Dalian people") manufactured by Tram Factory of Dalian, in Dalian.
Boston MBTA Type 8 Trolley
Bucur LF
Cegielski 118N "Puma" (>60% low floor)
City Class LRV
Hedley-Doyle Stepless car (1912)
Imperio
RTE 2009
SEPTA PCC II (loading platform)
Transtech Oy Artic Trams
United Streetcar trams
V3A-93-CH-PPC
Tram 2000 Be 4/6 (not low-floor, but due to the high platform is wheelchair access)
GTZ8-B Vamos
HCP Puma
M31 on Gothenburg tramway (reconstruction with low-floor middle article)
Fukui Railway F1000 (ja福井鉄道F1000形電車)
Hiroden 1000 series (II) (ja:広島電鉄1000形電車 (2代))
Hiroden 5100 series ja:広島電鉄5100形電車)
Kumamoto City Tram 0800 (ja:熊本市交通局0800形電車)
Kumamoto City Tram 9700 series (ja:熊本市交通局9700形電車)
Man'yosen MLRV 1000 (ja:万葉線MLRV1000形電車)
Okayama Electric Tramway 9200 (ja:岡山電気軌道9200形電車)
ja:SWIMO
Toyama Chiho Railway 9000 series (ja:富山地方鉄道9000形電車)
Toyama Light Rail TLR 0600 (ja:富山ライトレールTLR0600形電車)
Newag Nevelo
NGT6DD-ER on Dresden tramway
Serie 3800 de FGV on Valencia tramway/CCFL fleet series 501-510 on Lisbon tramway
