Freight Trains
Contents
Freight trains
Q. What are the typical freight loads carried by IR?
IR carries the entire gamut of goods, ranging from parcel traffic and small consignments, agricultural products, raw materials like iron ore and petroleum, and finished goods like automobiles. Over the last few decades, IR has made an effort to move away from small consignments or piecemeal freight, and to increase the number of block rakes where a shipper contracts for an entire rake assigned to carry a shipment. These are more profitable for IR as the rake does not have to be split up into or amalgamated from individual wagons going to or coming from different points, saving on marshalling time, transit time, and scheduling. Most of IR's freight revenue now comes from such block rakes carrying bulk goods such as coal or cement. A typical load (full rake) consists of 40 BCN wagons (2200t). Sometimes half loads (mini-rake) of 20 BCN wagons (1100t) are also available for contracts (see below for more on the mini-rake scheme).
In late 2004, some of the specifications for wagon loading were modified, so as to allow greater loads to be carried. For materials such as iron ore, an additional 4t can now be loaded, allowing a BOXN wagon to carry 62t.
Of course, IR does also carry container traffic and also smaller consignments, and there has been talk recently [10/01] of possibly re-entering the piecemeal freight business actively. Some dedicated parcel trains have been introduced. Parcel vans are still used a lot for small consignments; these vans are generally attached to passenger trains. They used to be more numerous in the past, but had been diminishing in importance in the 1980s and 1990s as IR focused on larger loads of freight.
[4/00] High-capacity parcel vans ('Green Parcel Vans') have been used in special-purpose rakes intended for carrying fruits and vegetables. The high-capacity parcel van carries 23t as opposed to the ordinary parcel van which carries 18t of goods. Single high-capacity parcel vans have been seen attached to passenger trains (e.g., GT, Lokshakti and Karnataka Exps., Saurashtra Mail, Flying Ranee); the vans are marked 'Blue Parcel Service' and have a dark-blue livery. Recently [1/03] new parcel vans formed by converting old general passenger stock (GS coaches) have been spotted at various places. These are being used for transporting cars and other automobiles.
Refrigerated parcel van service is available on a few sections. One such service proposed [2/03] for the Ernakulam-Thiruvananthapuram Jan Shatabdi will have a refrigerated parcel van that can accommodate 5t of frozen goods at -20C and 12t of chilled goods at +4C. This coach, manufactured by RCF, has a maximum allowable speed of 130km/h and has a diesel-powered refrigeration unit that can run for 15 days without refuelling. Similar services are expected to be introduced on most major routes. RCF plans to produce 9 of these refrigerated vans in 2003. CR and WR are also introducing such services. Now [10/04] IR has around 10 of these new design refrigerated vans.
In addition, a mini-rake scheme has been introduced [7/03] where loads smaller than full freight rakes (usually half-size, i.e., 20 wagons, also known as half rakes) are booked for transport by IR at full train-load prices, for distances up to about 300km with connecting services for transshipment to road transport. Not only is the half-rake service more convenient for many industrial concerns, the number of sidings at goods sheds and transshipment points where half-rakes can be loaded or unloaded is much larger than the number of sidings where full rakes can be handled.
Bulk freight transport rates also vary based on the number of times a rake may be loaded or unloaded. A so-called two-point rake is one that can be loaded or unloaded at two points, usually a half-rake at a time, at approved combinations of two loading or unloading locations.
Some freight rakes are used continuously in dedicated operations over a closed loop journey. These are known as closed-circuit rakes, and typically consist of 40 BCN or BCNA wagons (cement), or 58 BOXN wagons (coal), or 48 BTPN tankers (petroleum products).
The 'Green Bogey' (Green Bogie) service provides for the transport of perishable agricultural products (fruits and vegetables) in refrigerated and non-refrigerated wagons attached to passenger trains.
Q. What is 'Scale R' or 'Scale S', etc., in the context of parcel service?
IR has several freight rate scales for parcel traffic. Scale R or Rajdhani Parcel Service is applicable to parcels carried on the Rajdhani Express trains and thereby being assured of the speediest delivery of all IR's services. Scale P (Premium Parcel Service) applies to parcels carried on certain Shatabdi Express trains, certain other Mail/Express trains, and all Special Parcel trains (including the Green Parcel vans, Blue Parcel Service, etc.). Scale S (Standard Parcel Service) applies to all parcels carried on other passenger trains. There also used to be a Scale E (Economy Parcel Service) which was applicable to parcels carried on ordinary passenger trains, but that has since been abolished [3/05] and the category merged with Scale P. Newspapers, magazines, and certain other goods always get classified as Scale S traffic (earlier, Scale E).
Q. How are freight trains numbered or named?
The rakes are assigned names in alphabetic sequence starting with a name that begins with an 'A' for the first formation out of a marshalling yard after 0100 hrs, along with a number. This designation can change if the rake is broken up at another yard and regrouped. Thus, freight trains have names such as 'Ahmedabad 10', or 'Bombay 21', or 'India 38'. The letters 'J' and 'U' are not used, so that there are 24 letters available, one for each hour of the day. The number following the alphabetic part of the name indicates the time (minutes past the top of the hour) when the train departed the yard; e.g., 'India 38' is a freight train that left the yard at 0938 hrs. Trains leaving between midnight and 0100 hrs use the letter 'Z'. The words used to signify the letters of the alphabet are not standardized; 'Z' could be indicated by 'Zebra' or 'Zimbabwe'.
Some special freight trains are named differently (e.g. the Shalimar Special out of Mumbai (Wadi Bunder to Shalimar near Calcutta), or the 'Salt Cotours' freight (Wadi Bunder to Salt Cotours near Chennai)); these tend to be 'privileged' trains and they carry goods with guaranteed delivery schedules. The 'Ahmedabad Arrow' used to run between Bombay and Ahmedabad.
Other special freight trains include the 'Freight Chief' and the 'Super Link Expresses'. CONCOR introduced several new dedicated timetabled container trains in 2000 (Shalimar - Chennai, Shalimar - Hyderabad, Cossipore - New Delhi) and 2001 (Cossipore - Haldia, for international container freight), with more planned (Shalimar - Mumbai, Shalimar - Nagpur).
Recently [12/00] special timetabled parcel trains have been introduced by SER. One is the 'Dakshin Parcel Express' between Calcutta and Chennai, and another is the 'Pashchim Parcel Express' between Calcutta and Mumbai. These run at 90-105km/h. The 'Millennium Parcel Express' is slated [5/01] to run between Chennai and New Delhi, and also perhaps Shalimar - Ahmedabad, Shalimar - Sanatnagar, Sanatnagar - Tughlakabad, and Turbhe (New Bombay) - Shalimar.
Q. Who carries container traffic in India?
Most rail container traffic in India is handled by CONCOR (the Container Corporation of India) which until recently was the only such organization. CONCOR is a public-sector concern, but it maintains its own fleet of wagons and other assets that are separate from IR's, although the traffic moves on IR's tracks.
Recently [2/06] the government has given approval to the Pipavav Rail Corporation (PRCL) to offer container services in India. It is expected that PRCL will run container services from the ports of Pipavav, Mundra, Chennai/Ennore, Vishakhapatnam, and Kochi (Cochin). PRCL is a joint venture between IR and the Gujarat Pipavav Port Ltd. Originally, PRCL was set up to construct and operate a 270km BG railway line between Pipavav port and Surendranagar on the Western Railway.
Private operators [8/07] Private companies have only very recently been given approval to operate in India. Generally speaking the private companies are given limited licences to operate container services on specific routes and for a specific number of years. In April 2007, Boxtrans Logistics, belonging to the JM Baxi Group, became the first private player to operate container services, with a rake of 45 Texmaco flat wagons running between Cossipore (ER) and Loni near New Delhi and Mundra port (Gujarat). The initial runs carried about 90 TEUs. Boxtrans also expects to run services on the Loni - Vishakhapatnam route. Its licence allows it to run on all routes except the premier New Delhi - JNPT route. It is expected to maintain 3 rakes of its own. Another company, APL (formerly American President Lines), belonging to the Singapore-based Nepture Orient Lines began container operations in May 2007 with a rake from Loni to JNPT. APL holds a so-called 'Category 1' licence allowing it to run container services on all routes in India, for a period of 20 years. APL is initially buying seven 45-flat-wagon rakes from Titagarh Industries. A joint venture between Hind Terminals (of the Sharaf Group, UAE) and MSC Agency (belonging to the Mediterranean Shipping Company, Geneva) also has a Category 1 licence. Another private operator, Innovative B2B Logistic Solutions, has a limited licence to run container services on some routes. Other licensees include Reliance Infrastructure Engineers, Adani Logistics, Central Warehousing Corporation, and Delhi Assam Roadways Corp.
Q. What are CONTRACK trains? And ConRaj trains? And CARTRAC?
Recently [1999] CONCOR has begun running some fast (up to 100km/h) guaranteed delivery container freight trains on certain routes (35 rail corridors have been identified as suitable for such service). The rakes consist of 5-wagon groups of flat cars; the flat cars are low flat cars which allow loading 'Tallboy' containers.
A particular freight service of this kind inaugurated recently [6/00] goes by the name of CONTRACK and is a time-tabled weekly train between Shalimar Terminal and Tondiarpet (Chennai).
Some of the fast (up to 100km/h [8/00]) freight trains, especially on the Mumbai-Delhi route, are informally named 'Con-Raj' (for Container Rajdhani). Some of these even go straight through Vadodara without a halt, with crew changes only at Valsad and Godhra.
CONCOR has obtained several high-speed flat wagons which are rated for service at 100km/h. (These are also known as 'low belt container flat wagons', and abbreviated 'BLC'.) These have several advanced features, such as automatic twist locks, slackless drawbars, and small-diameter wheels allowing a low bed height. These are currently [12/00] in use on the Tughlakabad-Mumbai container route for the Con-Raj trains mentioned above. More are being ordered, under the auspices of a World Bank loan and the IBRD. Newer versions [9/04] have automatic load sensing devices to allow optimum braking under varying loads. The wagons have a single-pipe air-brake system.
CARTRAC is the name given to CONCOR's automobile transport service. It uses converted passenger coaches to hold automobiles in two decks. A typical CARTRAC rake has about 21 such modified coaches.
Q. What is the Dedicated Freight Corridor (DFC)?
The Dedicated Freight Corridor is a project for new railway lines exclusively for carrying freight isolated from normal IR traffic and passenger trains. Conceived in 2004-2005, planning began in 2006, and in 2007 initial proposals have been drawn up. In the first phase, the Western Corridor will connect the Jawaharlal Nehru Port to New Delhi via Vadodara, Ahmedabad, Palanpur, Jaipur, and Rewari and further on to Tughlakabad and Dadri. There will also be a link between Dadri and Khurja, and feeder routes connecting other ports of Gujarat. There will also be four logistic terminals, one each near New Delhi, Jaipur, Ahemdabad, and Vadodara. The Western Corridor is expected to carry mainly container traffic. The Western Corridor is expected to be unelectrified, using diesel traction. The Eastern Corridor is expected to connect Ludhiana to Sonnagar via Ambala, Saharanpur, Khurja, Shahjahanpur, Lucknow, Allahabad, and Mughalsarai. The primary feeder routes for this will be from Sonnagar to Durgapur via Gomoh, Sonnagar to Tatanagar via Garhwa Road, and Barkakana to Bokaro via Chandrapura. Eventually it will also connect to a new deep-water port off the coast of West Bengal near Kolkata. The Eastern Corridor is expected to carry more heavy mineral traffic and less container traffic. The Eastern Corridor is expected to be electrified. The entire DFC project will include 2,700km or so of exclusive freight lines (new construction), and about 5,000km of feeder lines that will include some new construction and many existing lines that will be upgraded. It is expected that trains running on the DFC lines will be up to 1.5km long (100 wagon rakes) and running at up to 100km/h. Double-stacking of containers is expected to be the rule, especially on the Western Corridor which will be unelectrified. Transit time for freight between Mumbai and New Delhi is xpected to drop to about 36 hours from the current 60 hours. In the busiest freight routes such as Ahmedabad - Marwar, the number of freight trains running is expected to rise from 15 each way each day (currently) to 72 each way; between JNP and Vadodara the increase will be from 9 to 49. Expected completion time for the first phase of the DFC project (the routes described above) is around 5-7 years (i.e., completion by 2012-2014). RITES is the agency carrying out the initial feasibility studies for the project.
Q. International freight: Are there direct freight trains running between India and neighbouring countries?
Freight trains run regularly between India and Pakistan via the Attari (Punjab) - Lahore route. The Munabao - Khokhrapar route is under consideration [2007] for goods traffic (it is currently only used for the Thar Express passenger traffic). Freight trains have also been running regularly between India and Bangladesh on the Gede-Darshana and Petrapole - Benapole routes. Another route connecting India and Bangladesh is Singhbad (India) - Rohanpur (Bangladesh). The Bongaon (India) - Jessore (Bangladesh) direct BG route has been proposed, and needs a 10km link constructed between Akhaura and Agartala. Nepal is connected to India by rail by the Birgunj - Raxaul line. See the international section and also the international links list.
Q. How heavy are the freights carried by IR? What are the heaviest freights?
[3/99] Among the heaviest freights regularly hauled in India are the 4700+ tonne loads hauled by two (sometimes one, depending on the gradient, etc.) WAG-9 locos in the Dhanbad Division. Earlier, these freights required multiple WAG-5 locos to haul them. Typical heavy freight trains in many sections use two or three WAG-5's at the front and two or three WAG-5's at the rear. Iron ore trains on the Kulem-Londa section, as well as other heavy freights in other sections such as on the SER can have up to 7 locos, for instance with 3 at either end and 1 in the middle, connected and operated through a system known as 'Locotrol'. The Kirandul-Kottavalasa line, before it was electrified, often had many freight rakes hauled by 5 or 6 diesel locos (1960s). (Today 2 or 3 WAG-5 locos are usual for these.)
[5/01] On May 17, 2001, a single WAG-9 achieved a top speed of 100km/h while hauling a rake of 58 BOXN-HA wagons (4700t) on the Sonenagar-Mughalsarai section of ER. The 123km section was covered in 100 minutes, at an average speed of 72km/h.
Trials have been conducted with a single WAG-7 hauling a 6000 tonne rake on level track near Gomoh; 5500t rakes have sometimes been hauled double-headed by WAG-9 locos; and 5500t rakes have also been hauled by two or three WAG-7 (?) locos. In 1998 a single WAM-4 hauled a 9000t (!) rake near Ghaziabad. In the early 1990s, a kilometer-long coal rake for NTPC's Dadri power plant was hauled on the Grand Chord.
Diesel traction: a single WDG-4 has been used to haul a 4700t rake (58 BOXN wagons).
'Midhaul' operations where locomotives are used in the middle of a rake are not common in IR. Locos are more often added at the front and rear of a rake. SCR has run [2/02] some trials using up to 7 locomotives (3 in the front, 3 at the rear, and one in the middle) for a 54-wagon rake on the Castle Rock - Kulem ghat section. Trials on the Hassan-Mangalore section with 58-BOXN wagon rakes were carried out with six WDG-3A locos, 3 in the front and 3 at the rear. Even though the newer locomotives such as the WAG-9 or WDG-4 can haul these heavy loads singlehandedly, many of the older bridges and other structures on IR's lines cannot withstand the higher longitudinal stresses that these locos exert, hence often these loads are hauled by multiple lower-powered locos. Brake power is also an issue on gradients. Three WDG-3A locos are said to be able to keep a fully-loaded 58-BOXN rake at 30km/h on a 1:50 down gradient using train brakes and dynamic brakes.
The BOXN-HA wagons (see the section on wagon types) was planned for heavier axle-loading and would have eventually allowed the routine hauling of 5220t rakes without the need for longer sidings or loops; however the experiments with this wagon type didn't work out and they were never manufactured after the initial batch of about 301.
Top Speeds : [Times uncertain here] For 4700t loads on level track: A WDG-2 can attain 68km/h in about 56 minutes (? not certain); a WDG-4 can reach 82km/h in 30 minutes; a WAG-5 can attain a top speed of 80km/h in 33 minutes; for a WAG-7, the figures are 92km/h and 38 minutes (or 70km/h in 15 minutes); and for a WAG-9, 100km/h and 17 minutes. In 2000, successful trials were conducted of running BOXN wagon rakes at 100km/h on the Gomoh-Mughalsarai section, and even up to Ghaziabad.
Goods trains on mainline BG routes are generally restricted to 75km/h, with a few exceptions and special operations. (Parcel vans and milk vans or refrigerated vans for perishables attached to passenger trains can of course go faster.) the average speeds of goods trains on the main trunk routes are around 40-45km/h. There is now [9/04] a proposal to raise the maximum permissible speed limit for goods trains to 100km/h on the trunk routes connecting New Delhi, Mumbai, Chennai, and Kolkata. These six routes (the quadrilateral and its diagonals) total about 10,000km, about 15% of the total IR network, but they account for 75% of the total freight traffic. The raising of the speed limit is expected to raise the average speed to 55km/h, which can potentially increase the utilization of the track substantially.
Q. Do double-stacked container trains run on IR?
IR has only recently [3/06] begun running a few double-stacked container trains. This is primarily because most of IR's main routes are electrified and raising OHE clearances is not permitted under the present Schedule Of (moving) Dimensions. Other reasons include low axle loads permitted on certain lines and types of wagons (20.32 tonnes on most lines and for most wagons, and 22.9 tonnes for few routes and type of wagons).
RDSO has been exploring the possibilities for double-stacking and some trials have been run. Normally, BLCA and BLCB flat wagons used for 9.5' high containers have 840mm diameter wheels with a floor heigh tof 1009mm above the rails. A single rake (45 BLCA/BLCB) can carry 90 20' long ISO containers or 45 40' long containers and this standard configuration can run at 100km/h on most of the important IR routes. In late 2003, RDSO ran trials on the Sidhapur - Umerdasi section of WR using double-stacked 40' long (and 9.5' high) containers on unmodified BLCA/BLCB wagons. Satisfactory ride characteristics were observed up to 85km/h on straight track, and also at lower speeds in yards, over complex points, and on 2-degree curves. The vertical clearance needed for double-stacking is a minimum of 6809mm from rail level, or about 7m. RDSO has submitted reports on this to the Railway Board and occasionally [2004, 2005] IR has made reference to the possibility of double-stacking, but this had not materialized anywhere except for extremely limited trials until 2006, when the first double-stacked container service was begun between Jaipur and Pipavav (starting on March 24, 2006). Jaipur - Pipavav was chosen because of the lack of electrification which eliminated the height constraint, and easy elimination of other obstructions which might have infringed on double-stacked train moving dimensions (and of course the availability of container freight from Pipavav port). The Jaipur-Pipavav section uses the usual BLCA/BLCB flat wagons for the containers. It is likely that other sections where double-stacking is introduced will see the use of different wagons with lower floors to allow vertical clearances to be met. Axle loads are expected to rise to 32.5 tonnes for double-stack container trains.
CONCOR is [8/07] in an agreement with Gateway Rail Freight, Pvt Ltd., to construct and operate a rail-linked double-stack container terminal at Garhi Harsuru near Gurgaon in Haryana, connecting the National Capital Region to the western ports.
[6/07] The proposed new wagon factory to be set up at Dalmia Nagar in Bihar is expected to manufacture 32.5 tonne axle-load wagons which will be used for double-stack container trains.
[4/07] Even triple-stack container trains with special-purpose automobile-carrier containers have been proposed for the New Delhi - Pune route. The railway ministry announced [4/07] a pilot project to run such triple-decker container trains to carry cars, scooters, and motorcycles in preparation for the eventual operation of such trains on the western section of the proposed Dedicated Freight Corridor (Mumbai - Ahmedabad - Palanpur - Rewari). The triple-stack trains are expected to be hauled by diesel locomotives as this western freight corridor is (in the initial planning stages, anyway) expected to be unelectrified.
Q. How has IR developed its hauling capacity?
Rakes of the old freight wagons, classified 'CG', for Covered Goods, consisting of the old 4-wheeled C or CR wagons) up to 1850 or so tonnes (2350t for some types of wagons). With the introduction of bogie stock, mixed CRT/CRC/BCX rakes became more common and brought the maximum up to 2750 tonnes. As noted above, even today the standard load for a typical shipment by a 'full rake' of miscellaneous goods is about 2200t.
The introduction of bogie wagons and air-braked stock has allowed larger and heavier formations to be hauled, and 3660t rakes of box wagons became common. The so-called 'Jumbo' rakes, consisting mostly of BCX and similar bogie stock are up to 3500-3750 tonnes (these are air-braked today, but vacuum-braked rakes of this size have been used), and beyond these are what are known in IR parlance as 'Super-Jumbo' rakes, carrying up to 4500-4700 tonnes. The super-jumbo rakes consist entirely of the newer BCX/BCN/BCNA/etc. wagons and are air-braked.
The 'Green Arrow' rakes have only BCN/BCNA wagons, up to about 40 of them. The name comes from the green paint scheme used for these air-braked wagons. Forty BCN wagons are about the limit for most parts of IR's network because of the restriction imposed by the lengths of loops where freight trains can be diverted to allow passenger trains to pass. The standard loop length is 650m, although many places are now getting loops of 900m to cope with freight formations that are up to 850m long.
BOXN formations up to 58 cars are also common (again, this is the maximum length allowable on most loop lines). The 'Green Bullet' trains have BOXN rakes usually carrying a bulk commodity like iron ore for thermal power plants. (The ones carrying coal are often known as 'Black Bullet' trains.) BCNA rakes can be up to 58 cars too, but more commonly 40+ cars or so. BCN wagons being a bit longer, only 40 cars or so are formed into a single rake.
In several places, IR has run, as experiments, longer freight trains formed by combining two or three freight rakes for part of a route and then splitting them later as they go on to their respective destinations. However, when running combined the extra-long rake has to be scheduled carefully as it places severe constraints on the movement of all other traffic on the same track because it cannot fit on any loop at any station, and any problem with the rake can result in major delays.
Upgraded versions of the BOXN wagons (class BOXN-HA, see the section on wagons) with payloads of 66t (and axle loads of up to 23.5t are planned to be run on several sections after track upgrades. Sixteen sections have been identified for this [4/05]:
Gua-Barajamda-Rajkharasawan-Sini-Chandill Gardhrubeswar-Joychandpahar-Damodar-Burnpur-Asansol, Bondamunda-Sini-Adityapur, Bolanikhadan-Barajamda, Bondamunda-Barsuan, Bimalgarh-Kiriburu, Bhilai-Dalli Rajhara, Damodar-Kalipahar, Padapahar-Banspani, Bondamunda-Nawagaon-Puranpani, Bhilai-Ahlwara, Waltair-Kirandul (the 'KK' line), Vasco-Hospet-Guntakal-Renigunta-Chennai, Nawagaon-Hatia-Muri-Bokaro, Purulia-Kotshila, Daitatri-Jakhapura-Paradeep and Sambalpur-Titlagarh-Rayagada-Vijayanagaran-Visakhapatnam.
Q. What is the state of intermodal transportation in India? Are roadrailers, road trailers on rails, etc. used in India?
Currently [7/00] a trial Wabash / Kirloskar roadrailer runs between Konkan Railway (or JNPT) and Nagpur. Konkan Railway has also made some trials of TOFC (trailer on flat car). Intermodal cars are used quite a bit. They are configured with 6 trucks for 5 cars, but double-stacking is not used as the floor height of the cars is usually the same as for regular COFC (container on flat car) services. CONCOR does have flat cars with low bed height for Tallboy containers. (Currently [2/02] around 1875 flat cars in its fleet; to increase by another 1000 or more in 2002.)
Spine cars, well cars, freight DMUs, CargoSprinter, etc. are not in use in India currently. [7/00]
Konkan Railway pioneered the 'roll-on, roll-off' ('RORO' or 'RO-RO') concept in India on its route between Mumbai (Kolad) and Goa (Verna). Starting in 1999 with 5 trucks being transported at a time, today [1/05] the service handles 50 trucks on its route each day. In this service, trucks belonging to commercial private trucking companies loaded with their goods drive on to a rake of flat cars and are carried (trucks and their cargo, and their drivers!) by train to the destination where they simply drive off the train; this obviously eliminates a lot of time lost in intermodal transshipment. Loading and unloading at either end can be as short as 10-15 minutes. The RORO rake normally achieves speeds of about 75km/h. The Kolad-Verna stretch takes about 10 hours with RORO while it can be a full day's driving or more if the trucks take the road instead. The trucks are restricted to 25 tonnes for 2-axle trucks and 40 tonnes for 4-axle trucks. RORO service is also available now until Mangalore (Surathkal) on the KR route. Recently [7/04] it was proposed that KR get monopoly rights to operate such RORO services on the rest of the IR network. Mumbai-Ahmedabad and Mumbai-Kochi are said to be among the routes being considered for this.
Q. How are the different kinds of freight cars classified?
.... And information on brakes, couplers, etc.
Please see the section on freight cars in the page on rolling stock for more details on wagons and their features, freight consists, etc.
Q. What's a 'mini-rake'?
A half-size goods rake (20 wagons), available for booking under special tariffs. See above.
Q. What's a 'jumbo' or 'super-jumbo' rake?
The term 'jumbo' originated when longer and heavier freight rakes could be hauled as better wagons (bogie stock), more powerful locos, and air-braking begin to come into use. A 'jumbo' rake is usually a BCX/BOY/etc. rake of up to 3500-3750 tonnes, which is much larger than the old 'CG' rakes which used to be limited to 1800 tonnes or so. All air-braked rakes of BCN/BCNA wagons up to 4500-4750 tonnes are known as 'super-jumbo' rakes. See the section on freight.
Q. Why does a goods train sometimes move backwards briefly before starting to move ahead from a stop?
There are a few different reasons that this happens. One reason (and the official one stated in working timetables) has to do with ensuring the couplers (CBC's) along the rake are all engaged and locked before starting off. The backward push forces the couplers to engage if they are loose, not fully engaged, or if the coupler pins had been inadvertently (or maliciously) lifted while the train was stopped.
Another reason is to compress the couplers along the length of the rake, so that when the loco starts moving forward, it has an easier time setting the wagons at the front in motion first before the rear wagons as the slack in the couplers plays out along the length of the rake -- it doesn't have to set the entire train in motion all at once. This is more important with poor track conditions where the loco cannot develope its full tractive effort before its wheels slips, or with older style bearings on the wagons which have much higher starting friction than the rolling friction encountered when on the move. Bad or older designs of bearings can also stick or bind and increase the starting resistance.
A third reason for the backward push is to release brakes where the blocks have stuck to the wheel treads (brake binding); once released by the backward push, there is no further resistance to forward motion. This was more of a problem in the vacuum brake days with poorly maintained brakes. Lastly, in the age before walkie-talkies, the backward push was a way to inform the guard at the rear end that the train was about to set off -- with really long rakes and noisy environments, horn signals might not always work.
Q. Why are there sometimes empty (or water-filled) tankers or other wagons at the end and beginning of rakes carrying petroleum products or other inflammable substances?
These empty or water-filled tankers or other wagons are known as 'guard wagons' and are intended to provide a safety buffer for the tankers carrying inflammable cargo. They are intended to take the brunt of any minor collision so that the tankers carrying the inflammable substances are not themselves damaged leading to possible explosions or major fires. At the head of the rake, next to the loco, another reason for providing guard wagons is to prevent inflammable vapours from the tankers from catching fire either from the hot diesel exhaust from the loco, or sparks at the pantograph from electric locos.
Q. Where are IR's goods yards, marshalling yards, etc.?
See the section on goods marshalling yards, CONCOR depots, etc.
