What is an 'A' class line, or a 'Q' class line, etc.?
The permanent way sections are classified by IR according to the maximum speed (or more precisely, the maximum speed proposed for the immediate future) that the tracks are capable of supporting. In most cases this classification is more an indication of the priority of the route and IR's plans for it in the future, rather than an indication of the speeds allowed on it today. Also, some small stretches of a line may have much higher (or lower) allowed speeds than the classification of the line might indicate because of local conditions, ghat sections, curves, etc.
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trivia section includes a list of the maximum speeds that some of these sections have been cleared for .
A class: Lines in this class are BG sections rated for speeds up to 160km/h. Some of these are:
Most of the New Delhi - Howrah line (via Grand Chord and Howrah-Burdwan Chord ('Rajdhani route')).
New Delhi - Bombay Central ('Frontier Mail route' or 'Golden Temple Mail route')
New Delhi - Madras Central ('Grand Trunk route')
Howrah - Nagpur - Bombay V.T. (CSTM)
Ratnagiri - Sawantwadi (KR)
Ratnagiri - Sawantwadi is a recent addition to this group [2004?]. Some IR publications still [2/06] do not list this section as an 'A' route.
Apart from the standard 'A' class lines mentioned above, IR is contemplating setting up some very high speed sections. Proposed sections include Mumbai Central - Ahmedabad, Bangalore - Chennai Central (these two for up to 200km/h, with the former also being a candidate for a Shinkansen-like service with trains at up to 300km/h -- although this is still in the early stages of planning), and Palwal-Bina, Ghaziabad-Mughalsara (these two for routinely running passenger trains up to 160km/h, and freights at 100km/h). These new sections will be fully fenced or grade-separated.
B class: This class allows speeds up to 130km/h. This class includes the following sections (from 1999 unless otherwise indicated):
Allahabad - Katni - Jabalpur - Itarsi - Bhusaval
Kalyan - Pune - Daund - Wadi - Secunderabad - Kazipet
Vadodara - Ahmedabad
Mathura - Ratlam
Ahmedabad - Ajmer - Jaipur - Bandikui - Rewari - Delhi
Sitarampur - Madhupur - Kiul - Patna - Mughalsarai
Howrah - Bandel - Barddhaman
Kharagpur - Waltair - Vijayawada
Kiul - Bhagalpur - Sahibganj - Barharwa
Delhi - Panipet - Ambala Cantt. - Kalka
Ambala Cantt. - Ludhiana - Pathankot
Ambala Cantt. - Moradabad - Lucknow - Pratapgarh - Mughalsarai
Agra Cantt. - Lalitpur
Kanpur-Agra (As of [2/00] there was a plan to upgrade this and Lucknow-Kanpur to 'A' and rate it at 140km/h.)
Virar - Vadodara - Godhra
Lalitpur - Bina
Khanna - Barharwa - Farakka Bridge - Malda Town
Wadi - Raichur - Arakkonam - Madras Central
Jolarpettai - Bangalore
Arakkonam - Jolarpettai - Salem - Erode - Coimbatore - Ernakulam
New Jalpaiguri - Malda Town (NFR)
Chennai Beach - Dindigul [2005]
Chennai Beach - Chennai Egmore (3rd line) [2005]
Bangalore - Dharmavaram - Gooty [2004]
Ghaziabad - Saharanpur [2005]
C class: This is not really a speed-rated class, but is the classification used for suburban sections of metropolitan areas.
CST Mumbai - Kalyan - Kasara
CST Mumbai - Kalyan - Karjat
CST Mumbai - Kurla - Panvel
CST Mumbai - Ravali - Mahim - Andheri
CST Mumbai - Ravali - Kurla
Churchgate - Mumbai Central - Borivali - Virar
Chennai Central - Basin Bridge Jn. - Veyasarapadi - Arakkonam
Chennai Central - Basin Bridge Jn. - Washermanpet - Chennai Beach - Tambaram
Chennai Central - Basin Bridge Jn. - Korukkupet - Tondiarpet - Tiruvottiyar - Gummidipundi
Chennai Beach - Thirumayilai
Sealdah - Dumdum - Naihati - Kalyani - Ranaghat - Krishnanagar
Sealdah - Sonarpur - Baruipur
Ballygunge - Budge Budge
Howrah - Dankuni - Saktigarh - Barddhaman
Howrah - Bandel - Saktigarh
Seoraphuli - Tarakeshwar
Dumdum - Barasat
Howrah - Panskura - Kharagpur
D-special class: BG lines rated up to 100km/h, with high traffic density or high expected growth in traffic. The following lines were identified as D-special routes in 1999 unless otherwise indicated:
Kharagpur - Midnapur - Adra
Barkakhana - Barwadih - Garwa Road
Tundla - Yamuna Bridge
Bolangir - Titlagarh
Gudur - Renigunta
Anara - Chandil - Kandra - Sini
Anuppur - Shahdol - Katni - Bina
Ahmedabad - Viramgam
Nagda - Ujjain - Maksi - Bhopal
Lucknow - Sultanpur - Zafarabad Jn - Varanasi
Delhi - Ghaziabad - Hapur - Moradabad
Lucknow - Kanpur (In [2/00], there was a proposal to upgrade this to 'A'.))
Chapra - Hajipur - Barauni
Raipur - Titlagarh - Vizianagaram
Guntakal - Tornagallu - Hospet (Hospet section added 2004)
Udhna - Nandurbar - Jalgaon
Gomoh - Chandrapura [2005]
Garwa Road - Chopan [2005]
Garwa Road - SoneNagar [2005]
Barauni - Katihar [2005]
Sambalpur - Talcher - Nergundi [2005]
Jharsuguda - Bolangir [2005]
Barabanki - Gonda - Gorakhpur - Chhapra [2005]
Champa - Gewra Road [2005]
Bilaspur - Anuppur [2005]
D class: BG lines rated up to 100km/h.
Salem - Bayappanahalli
Guntur - Donakonda - Guntakal
Vikarabad - Parli - Parbhani
Vijayawada - Bhimavaram - Nidadavolu
Secunderabad - Dronachalam
Jodhpur - Marwar
Diva - Vasai Rd (Was E-Special until recently [2004].)
Pen - Roha
Kumedpur - Katihar Jn
Rewari - Hissar
Kalumna - Nagda (via Itwari)
Kota - Ruthiyai
Bina - Guna - Ruthiyai
E-special class: BG lines with sanctioned speeds below 100km/h, with high traffic density or high expected growth in traffic. The following lines were identified as E-Special routes in 1999:
Garwa Road - Sonnagar
Panskura - Haldia
Talcher - Rajatgarh - Salegaon - Nergundi
Cuttack - Paradeep
Radhakishorepur - Rajathgarh - Barang
Kapilas Road - Salegaon
Radhakishorepur - Machapur
Kirandul - Koraput
Rajakharshwan - Dongaposi - Padapahar - Barajmda - Gua
Bondamunda - Bimlagarh - Barsuan - Kiriburu
Kandra - Gomhauria (Gamharria)
Champa - Gevra Road
Marauda - Dallirajhara
Urkura - Sarona
Bhojudih - Mohuda (Grand Chord)
Chandil - Muri - Bokaro - Rajbera
Padapahar - Banspani
Jharsuguda - Sambalpur - Bolangir
Barajamda - Bolanikhandan
Muri - Barakakana
Talgoria - Bokaro City
Kota - Ruthiyal
Diva - Vasai Road (formerly [1999]; now D class)
Tornagallu - Hospet (formerly [1999]; now D class)
Andal - Sainthia [2004]
Hatia - Muri [2004]
Mohuda - Gomoh [2004]
Koraput - Kottavalasa [2004]
Koraput - Singapuram Road [2004]
Sambalpur - Angul [2004]
Anuppur - Bijuri - Boridand [2004]
Boridand - Bisrampur [2004]
Durg - Marauda [2004]
Londa - Vasco [2004]
Dewas - Maksi [2004]
Gandhidham - Bhuj [2004]
Dornakal - Bhadrachalam Road - Manuguni - Kerapalli & Singereni collieries [2004]
Sanathnagar - Maula Ali (bypass line) [2004]
E class: This class includes all other BG lines with sanctioned speeds below 100km/h.
Q class: These are MG lines rated for speeds above 75km/h and traffic generally above 2.5 GMT. Some (such as Delhi - Jaipur) allowed speeds up to 105km/h or so (Pink City Exp., etc.) and had concrete sleepers and welded rails. The list of such lines from 1999/2000 is given below; gauge conversion has rapidly changed the MG picture in recent years.
'Q' class MG sections as of 1999/2000
Rewari - Ringus - Phulera
Ratangarh - Degana
Delhi Sarai Rohilla - Rewari - Ratangarh
Ajmer - Ratlam - Khandwa
Jaipur - Phulera - Ajmer
Bandikui - Agra Fort
Ahmedabad - Bhavnagar
Agra - Mathura - Bhojipura - Lalkuan
Bhojipura - Lucknow Jn
Villupuram - Thanjavur - Thiruchirapalli
Chennai Beach - Villupuram (added in 2000)
Dindigul - Madurai (added in 2000)
In addition to the above, these MG sections were in the 'Q' class in 1985 (incomplete list):
'Q' class MG sections as of 1985
Ratangarh - Rewari
Jodhpur - Jaipur - Agra East Bank
Kathgodam - Bhojipur
Bangalore - Hubli - Miraj
R class: These are MG lines rated at up to 75km/h. This category is further broken down into three classes based on traffic density: R-1, R-2, and R-3 (in decreasing order of traffic carried).
R-1 routes (traffic above 5 GMT/year) : As of 1985, this included Hospet - Hubli, Secunderabad - Guntakal, Londa - Marmagoa, Katihar - New Bongaigaon, Guwahati - Tinsukia, and Gandhidham - Palanpur. Only Gandhidham - Palanpur remained in this category by 1999. Katihar - New Bongaigaon and Guwahati - Tinsukia carry over 5 GMT / year, but are not counted as R-1 routes as they are slated for gauge conversion very soon [2004].
R-2 routes (traffic of 2.5-5.0 GMT/year) : As of 1985, this included Guntakal - Hospet, Guntakal - Villupuram, Tiruchirapalli - Manamadurai - Virudunagar, Purna - Secunderabad, and Jodhpur - Marwar. By 1999, the list consisted of just Secunderabad - Mudkhed, Guntakal - Bellary, Guntakal - Villupuram, Thiruchirapalli - Manamadurai - Virudunagar.
R-3 routes (traffic of 1.5-2.5 GMT/year) : As of 1985, this included Madurai - Rameswaram, Virudhunagar - Tenkasi, Dindigul - Pollachi, Ratangarh - Bikaner - Merta Rd., Muzaffarpur - Narkatiyaganj, and Birur - Shimoga Town. By 1999, the list consisted of Madurai - Rameswaram, Virudunagar - Tenkasi, Dindigul - Pollachi, and Ratangarh - Bikaner.
S class: These are all the remaining MG lines rated for below 75km/h and/or with low traffic densities (below 1.5 GMT/year).
There are no classifications like the above for narrow gauge tracks.
As mentioned above, these speeds are the maximum that the tracks are built to support. Actual running speeds are usually much lower because of other considerations (traffic on the line, signalling arrangements, curves, proximity to populated areas, presence of points and divergences / convergences, etc.). Based on this the maximum permissible speed is specified for each section of a route.
Normally only the main line can be traversed at that speed. Turnouts to diverging routes require a reduction in speed. Most turnouts have speed restrictions of 25km/h (1 in 12 or easier). Sharp turnouts (1 in 8, NG turnouts of 1 in 8.5, etc.) are limited to 15km/h or