CN ALCo/MLW locomotives — road switchers

  1. History
  2. Liveries
  3. RS-3
  4. RS-1
  5. RS-10/RS-10S
  6. RS-11
  7. RS-18
  8. Tempo units

David Othen has compiled this information with help from Leslie Ehrlich and Don McQueen. Several published sources were used including: "CN LINES", the CNRHA's magazine, "Canadian National Railway Locomotives" (Nos. 48-50, 1974-1975) by Ray Corley et al (courtesy of Don McQueen), "The Second Diesel Spotter's Guide" by Jerry A. Pinkepank, "The Diesel Spotter's Guide Update" by Jerry A. Pinkepank and Louis A. Marre, "The Canadian National Railways' Story" by Patrick C. Dorin, various editions of the "Canadian Trackside Guide" edited by Earl W. Roberts and David P. Stremes, several of the photo albums published by BRMNA (Calgary) and various issues of Railroad Model Craftsman, of "CN Movin" and of Extra 2200 South. Many thanks to everybody who has contributed photographs from their collections — Ed Barry, Ron Blumer, George Carpenter, Paul Charland, Steve Hunter, Bill Linley, Don McQueen, E.D. Motis, and Don Ward (their names appear on the large photographs). Please send corrections, extra information and photos for inclusion to David Othen (

History of purchases of ALCo/MLW Road Switchers

As Canadian National began to use diesels for their freight operations during the 1950s, the railway initially purchased A and B cab units but soon decided to turn to diesels with the road switcher type of carbody. Beginning in 1953 they purchased MLW four-axle (B-B) 1600 hp RS-3 and RS-10/RS10S Road Switchers. These were followed by 225 1800 hp RS-18s and 41 2400 hp C-424s. For rural branchline use, CN purchased 39 unique six-axle RSC13s and RSC24s (1000 and 1400 hp respectively). Then, beginning in the mid-1970s CN purchased 90 2000 hp M-420W and HR412 locomotives.

CNR also purchased American-built ALCo RS-3s and RS-11s for its CV, DW&P and GTE subsidiaries and two 1000 hp RS-1s for the GTW.


Unlike the switcher units, CN's Road Switchers built before 1961 were painted in the handsome green and yellow livery — green body (CNR Green No 11) with yellow (CNR Yellow No 11 commonly called "Imitation Gold") frame. The main body was green and on each side was a yellow stripe, curved at the ends, on which was "Canadian National" in black letters. On the ends of both the long and short hoods, there was a roughly triangular yellow area, with curved sides at the top and below this there was a curved V-shaped, yellow band that narrowed and dipped to a point. Near this point (sometimes above and sometimes below depending on the exact shape of the band) was the early diesel nose leaf monogram (CNR in white on a red maple leaf with a circular yellow background whose outside diameter is 28 inches). On units painted after late 1953, the 1954 round monogram with an outside diameter of 20 inches was used (the white "CNR" was replaced by "Canadian National Railways" in yellow). Several variations of the green and yellow livery exist because the drawings made by the manufacturers and later the CNR, beginning about 1956, had only partial dimensions. By 1961 the drawings were more detailed.

In 1961 the CN symbol (designed by Alan Fleming) and paint scheme appeared on new and repainted locomotives. The locomotive carbody was black with orange (CNR Orange No 11) hood ends and off-white (CNR Grey No 17) lettering and striping around the frame. In 1973 the first M-420W built, 2500, introduced the zebra-stripe scheme with orange cab and reflective yellow striping around the edge of the frame. This paint scheme was simplified in 1992 with a single white stripe and the CN North America map. However the map was not used on switchers and road switchers. All first-generation MLW Road Switchers were retired before the end of the century and only a few units were repainted in this livery.


CNR purchased its first MLW road switchers in 1953, a batch of 18 1600 hp RS-3s powered by the turbocharged 12 cylinder 244 engine (Y-7-a, MR-16a after 1954). These locomotives had louvered engine compartment doors. They were numbered 7830-7847, renumbered 1800-1817 in 1954, and renumbered again in 1956 to 3000-3017. At least nine RS-3s including 3000-3008 were later fitted with six exposed carbody air-filters in a horizontal configuration (the modifications were made to units assigned to the Central Region).

The first six units 7830-7835 (later 1800-1805 and finally 3000-3005) did NOT have dynamic brakes whereas 7836-7847 (later 1806-1817 and finally 3006-3017) had dynamic brakes in the short hood. These later units had extra louvers in the access doors and an additional full-bodied, vertical row of louvers on each side of the short hood closest to the headlight. They also had the dynamic brake exhaust grids on the roof centred along the length of the short hood. The photos of 3000 and 3009 show the differences in the short hoods of MR16a units without and with dynamic brakes.

All RS-3s on the CNR system were equipped with water-cooled turbochargers and so had a centrally located, crosswise exhaust stack. Some units were fitted with a winterization hatch cover over the radiator roof fan and some received an extended exhaust stack to reduce the exhaust fumes that entered the cab. During their lifetime, the headlights on many units were changed to twin sealed-beam headlights from the single headlight with two bulbs and the bell was mounted on the long hood.

PHOTOS: 3000 is seen in the green and yellow livery with the later (1954) monogram and twin headlight (at least on the short hood) on 2 March 1963 in Toronto. For comparison a colour photo of the unit as built — 7830 with a single headlight on the long hood at St Lambert QC in December 1953 — can be found on page 70 of Rail Canada Volume 1 (4th Edition). 3001 also in green and yellow with the later monogram and with the bell on the long hood is seen at Toronto on 25 May 1965. 3004 is seen in the black and orange livery on 5 May 1965 at Niagara Falls ON. Finally the photo of 3017 at Moncton on 13 September 1967 clearly shows the original louvered compartment doors.

CN 3000 CN 3001 CN 3004 CN 3009 CN 3017

In 1954 CNR purchased 23 more RS-3s and all units in this batch had a horizontal row of six exposed filters on either side of the hood. They were originally numbered 1818-1840 (MR-16b) and renumbered 3018-3040 in 1956. According to the CN Diesel Unit Data Book all units except 1818 (3018) and 1819 (3019) had dynamic brakes. The arrangement of the louvers and dynamic brake exhaust grids were different from those on the earlier dynamic-brake equipped units. There was no full-bodied, vertical row of louvers ahead of the access doors. Instead the forward access door had extra louvers so that there was a full bodied set of louvers. Also, the dynamic brake exhaust grids on the roof were closer to the headlight along the length of the short hood necessitating a raised section of the roof edge that broke the seamless rounded contour. The photos of CNR3019 and CN3022 show the differences in the short hoods of MR16b units without and with dynamic brakes.

PHOTOS: The exposed filters are seen on 3040, in green and yellow livery, (the date of the picture is not known but the location may be Truro NS) and also in the photo of 3020 in black and orange at Truro NS on 20 March 1963. Note that 3040 is fitted with a double-barrelled spark arrester (only two units — 3038 and 3040 — are known to have received this type of spark arrester between 1956 and 1963).

CN 3019 CN 3022 CN 3040 CN 3020

In 1954, CNR purchased, from ALCo, two RS-3s fitted with steam generators for the Central Vermont and numbered them CV1859-1860 (MR-16c). On each side of these units were five vertically arranged carbody filters in two of the engine compartment doors. Later, 1859-1860 were renumbered to CV 3900-3901 and then became CN 3900-3901.

PHOTOS: The first black and white photo shows CV1860 on a freight train at Milton VT on 22 April 1955.. The second black and white photo shows 3900 still in CVR livery at Brockville ON on 13 April 1958 while it was laying over during the weekend from assignments pulling trains 24-25, the MOCASSIN (Brockville-Montreal), then Canada's oldest regularly scheduled passenger train. It is seen again, still in green and yellow, but now lettered Canadian National with a Montreal commuter train at Mount Royal Avenue in July 1962. Later we see it in black and orange on 12 October 1968 in Toronto and on 20 April 1969 with a railfan tour.

CV 1860 CV 3900 CN 3900 CN 3900 CN 3900

Also in 1954 CNR purchased two ALCo RS-3s with dynamic brakes in the short hood for the GTE. These two locomotives have a similar layout of carbody filters to the two CVR units. They were numbered GT 1861-1862, class (MR-16d). The black and white photo shows GT1861 in green and yellow livery at Portland ME on 15 November 1955. A photo of the left side and short hood of the same loco can be found in Extra 2200 South #48 page 18. In 1956 they were re-numbered to 3041-3042. In 1957, they were transferred for nine months to the Central Vermont and re-lettered Central Vermont while retaining their new numbers. By the end of the year, they became CN 3041-3042. CN 3041 is seen in black and orange livery at Toronto ON on 9 May 1965.

GT 1861 CN 3041

All RS3s were retired by 1969 except 3900-3901 that were retired in 1973 and 1971 respectively. 3900, heavily stripped, was still in the scrap line in Moncton in 1979 as seen in Ed Barry’s photos.

CN 3900 CN 3900


Three years after purchasing the four RS-3s, CN bought for GTW two turbocharged 1000 hp RS-1s, powered by 6-cylinder 539 engines and equipped with steam generators. They were built by ALCo and delivered in October 1957 as GTW1950-1951 (MR-10e). These were the last RS-1s built in the US for a US Railroad (after 17 years of continuous production). They had exposed carbody filters (introduced in 1954) instead of louvers and a unique small two-inch lip at the top of the hood. They also had two sets of horns on the top of the cab roof (it must have been noisy inside the cab!).

PHOTOS: These features are clearly seen in the photos of 1950, in green and yellow livery, at Durand MI on 25 June 1966 and in December 1966. The same unit in black and orange livery is seen at Milwaukee Junction, Detroit MI in May 1972. 1950 was retired in mid-1978 and parts were used to keep 1951 going to the end of the decade. It was sold in August 1981.

GT 1950 CN 1950 CN 1950


In late 1954 MLW introduced the RS-10 which had the same 12 cylinder 244 engine as the RS-3 but in a radically altered carbody with a much higher hood. The hood was almost level with the cab roof and gave more space for additional equipment such as dynamic brakes and steam generators. It had a more angular appearance with flat ends (rounded where they joined the sides), a feather-edge hood peak, two angled number boards (with sand-box lids below) on each end and a prominent intercooler covered with a grille just behind the radiator shutters. As built, there were two layouts for the carbody filters. Units without dynamic brakes, or with dynamic brakes in the short hood, had three square carbody filters in a horizontal line close to the intercooler (see the photos of 3818 in green and yellow livery — it had dynamic brakes in the short hood and so had the extra louvers on the left hand side of the short hood). Units with dynamic brakes in the long hood had the three square carbody filters plus two closely spaced filters near the cab (see photo of 3091 which has dynamic brakes in the long hood). In 1955 when CN purchased more 1600 hp road switchers they acquired the RS-10/RS-10S model and over the next three years bought a total of 51 units. The first 15 units had Amplidyne excitation (RS-10) but subsequent units had the more reliable Static excitation and were designated model RS-10S. The RS-10/RS-10S was unique to Canada and was purchased by CN, CP, ON and PGE.

The first units (model RS-10) were numbered 1863-1885 (MR-16e, f, g, h) and then in 1956 renumbered to 3043-3065 (in 1957, 3043-3057 became 3800-3814). The next units (MR-16j, k) were model RS10S and were numbered 3066-3093 (later, 3066-3073 were renumbered 3815-3822). None had steam generators.

The 3800-number series was created to identify units that were lightweight (228,000 pounds) and rode on lightweight MLW trucks (no prominent lateral leaf spring). Of these, 3807-3822 had dynamic brakes in the short hood. By contrast, units 3058-3093 weighed between 243 and 245 thousand pounds and of these 3058-3060 and 3074-3093 had dynamic brakes in the long hood. More information can be found in the article by Ken Goslett in Railroad Model Craftsman August 1994 pages 55-57.

Canadian National changed the layout of carbody air-filters and some units even had different layouts on each side!. Eventually most, if not all, units received the standard layout applied to the RS18 units (see later section) as shown in the photo of 3818 in its final years in the black and orange livery. All units had been retired by 1970.

PHOTOS: Heavyweight RS-10 (Amplidyne-equipped) 3061 is seen at Gordon yard, Moncton NB on the evening of 3 May 1968 and lightweight RS-10, 3804, is seen at Charny QC on 29 April 1967. Both units are in black and orange livery.

The right side of RS-10S (static excitation), 3084, which has dynamic brakes in the long hood, is seen in green and yellow livery at Charny QC on 3 August 1964. The left side of 3091, also with dynamic brakes in the long hood, is seen at Ottawa in March 1963. RS10S 3818 (note the later style of numbers) is a lightweight unit (note absence of lateral leaf springs) with dynamic brakes in the short hood and is also seen in the green and yellow livery in the early morning sunlight at Turcot, Montreal shortly after re-numbering (circa 1956). This left side view clearly shows the additional louvers (only found on the left side) and roof vents associated with the dynamic brakes in the short hood. The view of the right side of the same unit at Bridge (Ste Foy) QC on 7 July 1962 shows the absence of louvers on the right side of the short hood. The same unit is seen after repainting into the black and orange livery at Moncton NB on 14 September 1967. Note the change in the carbody filters.

CN 3061 CN 3804 CN 3084
CN 3091 CN 3818 CN 3818 CN 3818


In 1956 ALCo introduced the 1800 hp, 12-cylinder 251B engine and mounted it in a new carbody to produce the RS-11. The carbody was very similar to that introduced by MLW on the RS-10 except that it had deep notches in the ends of the hoods where the number-boards were located. CN purchased 15 of these units for the DW&P in 1956 and numbered them DW&P 3600-3614 (MR-18a) They originally had lightweight trucks but these were later changed to AAR Type-B trucks. In January 1965, 3609-3614 were transferred to the CV and in 1968, they were returned to the DW&P. Beginning in 1979, all the RS11s were transferred to the Central Vermont and eight (3600-3605, 3611-3612) were painted in Central Vermont livery but retained their original numbers. 3609 was the first unit to be withdrawn and was dismantled in 1980 at St Albans VT (see photo).

DWP 3609

An additional RS-11 (CV 3609:2) was purchased second hand from N&W in 1979. DW&P chop-nosed the short hood of 3608 at West Virginia in May 1979.

All RS-11s purchased new were built with 74:18 geared traction motors but many were later fitted with 65:18 geared traction motors that increased their top speed from 65 to 75 mph. They did not have a grille over the intercooler, instead they had chicken wire. There were three square carbody filters in a horizontal line and louvers in the short hood (I presume that they were fitted with dynamic brakes). By contrast, the former N&W unit, 3609:2, had five square carbody filters between the intercooler and the cab and there were no extra louvers in the short hood. See the photo of the left side of 3609:2 taken at St Albans VT in May 1980 and compare this with the photo of the left side of CV 3614 taken at St Albans VT in June 1982). By 1988, all units were retired and later some units were sold to shortlines.

LIVERIES and PHOTOS: These units have been painted in many different liveries. Initially they appeared in the original green and yellow livery with on both sides a large yellow rectangle with curved ends. Inside this rectangle, on two lines, was Duluth, Winnipeg and Pacific in black letters (see photo of 3604 at West Duluth MI on 2 July 1964). Beginning in 1962, they received the black and orange livery (3602 is seen on a northbound freight from Portland ME on 21 May 1980). Other liveries included:

  1. the bicentennial livery on 3605 (shown at Duluth on 3 July 1976);
  2. the all-red livery with two different lettering schemes — 3600 and 3614 were lettered D W & P whereas 3605 had the Delivered with Pride logo (see photos of 3614 at St Albans in October 1979 and 3605 at Duluth on 21 June 1977) This livery is sometimes referred to as the British Redcoat scheme;
  3. the black and grey stripped "Zebra" CN scheme on eight units (3606-3613) — photo shows 3609 at Portland ME on 29 October 1978;
  4. the red and blue "Deliver with Pride: livery on five units (3606-3608, 3610 and 3613 — the photos show 3610 with yellow reflective striping on the frame [date and location unknown] and 3608 with a chopped nose and white frame at Duluth on 3 September 1982; and
  5. the green and yellow livery of the CV (3611 and 3614 both at St Albans VT in June 1982). For comparison the ex N&W unit CV3609:2 is seen at St Albans VT in May 1980.

DWP 3604 DWP 3602 DWP 3602 DWP 3605 DWP 3614 DWP 3605 DWP 3609 DWP 3610 DWP 3608 DWP 3604 DWP 3614 DWP 3609


MLW also introduced the 251B engine in late 1956 and put the 12 cylinder 1800 hp version in the RS-10 carbody to produce the uniquely Canadian RS-11M (later renamed RS-18). CN purchased 131 units between 1956 and 1958 and numbered them 3615-3745 (MR-18b, c, d). In 1959 they purchased 30 more units fitted with a steam line (but not a steam generator) and numbered them 3100-3129 (MR-18e). Finally a further 64 units were purchased in 1959 and 1960 and were numbered 3830-3893 (MR-18f, g).

All units were equipped with a small, 1000 Imperial gallon, fuel tank but these came in two different styles. 3615 to 3745 had a longitudinal tank parallel to and well inside the locomotive frame. The air tanks were also mounted longitudinally. Units 3830 to 3893 and 3100 to 3129 had a transverse tank mounted near the cab end of the locomotive with the air reservoirs mounted transversely ahead of this tank. All units were equipped to run long hood forward. 3671-3745, 3830-93 and 3100-29 originally had lightweight MLW trucks but these were later changed to AAR Type-B trucks on almost all units. Dynamic brakes were fitted to 3830-3893 and 3100-3129 (all in the short hood) and can be identified by the additional louvers on the left-hand side of the short hood and on the roof (though the roof fittings seem to be smaller on some units).

The pilots on the front and rear of the 3100-3129 locomotives have a raised central section to accommodate the rigid steam line pipe, which is just above rail height.

As built, there were three variations of louver and filter arrangements on the RS-18 carbody in addition to the variations due to the presence of dynamic brakes in the short hood:

  1. 1957-8 style on 3615-3745 — five separate square filters in a horizontal line between the intercooler, which was covered with a metal grille, and the cab. See the photo of 3672 at Brockville on 10 August 1960.CN 3672
  2. 1958 style on 3100-3129 and 3830-3849 — the intercooler was covered with a metal grille and there was a three unit filter near the cab. See the photo of 3840 at Kingston on 1 April 1961. CN 3840
  3. 1959-60 style on 3850-3893 — the intercooler was covered with chicken wire and there was a three-unit filter near the cab. See the photo of 3865 at London on 4 July 1964. CN 3865

About 1963 Canadian National began to retrofit the RS10/RS10S and RS18 units-with a new layout of the filters — there were three square carbody filters in a horizontal line near the intercooler and a three unit filter near the cab. The covering over the intercooler was probably unchanged — those units that had a chicken wire covering seem to have retained it. 3615-3745 were modified about 1963-1964 and the other units except 3857 (later RSC-14 1760) were modified about 1971-1972.

The carbody air-filters were originally made of a black material but in the 1970s white filters with diagonal, silver stripes were introduced (see photo of 3643) and in the 1980s light blue filters were used (see photo of 3616).

Originally RS-18s 3615-3745 and 3830-3893 had traction motors with 74:18 gearing and a maximum speed of 65 mph. Some, possibly all units later received traction motors with 65:18 gearing and were allowed to travel at a maximum of 75 mph. The CN Mechanical Department Diagram sheets (mod 489) show all RS-18s changed to 75-65:18 with Issue B (c.1960-61) and those done were marked 75-65/18 on the cab side above the number. Later these markings appear to have been dropped, at least on some units.

Some of the 3830-3893 series were retrucked in 1975 and 1976 with six axle trucks to create RS-18ms or RSC-14s (see later section).

The last RS18 was retired in 1993 except for those converted to RSC14s. More information about RS18s can be found in an article by Bram Bailey in the Railroad Model Craftsman, February 1990 pages 60-64.

PHOTOS of 3615 SERIES: Note the longitudinal air reservoirs and fuel tank in the centre of the locomotive.

CN 3639 CN 3705 CN 3728 CN 3624 CN 3628 CN 3652 CN 3709 CN 3616 CN 3643

PHOTOS of 3830 SERIES: Note the transverse fuel tank and air reservoirs and the additional louvers on the left side of the short hood and on the roof to provide cooling for the dynamic brakes.

CN 3834 CN 3874 CN 3879 CN 3857 CN 3834

PHOTOS of 3100 SERIES: Note raised centre section of the pilot and steam pipe below.

CN 3112 CN 3115 CN 3118 CN 3117 CN 3834


Two RS18s with a steam generator car hauled the passenger trains between Sydney and Truro (until they were replaced by Railiners in the mid 1970s) and Matapedia and Gaspe (until replaced by F units in the 1980s). Re-geared units were also used on passenger extra trains throughout Atlantic Canada and the Central Region when sufficient F units or Railiners were not available.

The photos show 3662 and 3670 with the westbound train at Antigonish in the summer of 1973 and 3629 followed by VIA B and A units on a Montreal-bound train passing Grand Lake near Halifax on 4 August 1979.

CN 3662 CN 3629

Several units were fitted with special covers to keep snow out of the radiators when the locomotives were used in snowplough service. Two units are seen, both at Moncton: 3636 in black and orange on 24 March 1989 and 3633 in black and grey stripes on 6 February 1981. However not all RS18s used in snowplough service had these covers as seen in the photo of 3102 at Truro NS on 26 December 1983.

CN 3636 CN 3633 CN 3102


In 1967, 6 RS18s (3850, 3883, 3860, 3856, 3884 and 3887) were rebuilt with a Cummins head end power unit (HEP) in the enlarged short hood for use with the aluminium Tempo passenger coaches. 3860 is seen in the green and yellow livery, after rebuilding, at Ottawa in January 1968. The enlarged short hood occupied the space where the end walkway would normally be located and had a unique layout of grilles (see photos) including two large horizontal openings near the top of the short hood on both sides and additional cooling vents on the roof. The intercooler is covered with chicken wire.

CN 3860

The units became 3150-3155 (MRE-18g) in mid 1968 and were then painted in a unique livery — orange with the upper cab white and a grey CN symbol on the long hood. The MRE-18gs are seen in the photos of 3150 at London on 13 May 1972, of 3152 at Spadina, Toronto roundhouse in the early 1970s and of 3150 at Bathurst bridge in May 1980. Roof details are seen in the photo of 3154 at Hyde Park on 12 April 1970 and of 3155 at Spadina yards on 9 June 1983 with its peeling paint. Dual controls were fitted so that they could readily run either short or long hood forwards and they often ran in pairs as seen in the photo of 3150 and 3154 entering Toronto.

CN 3150 CN 3152 CN 3150 CN 3154 CN 3155 CN 3150

The units always ran hot especially in the summer. To improve the cooling of the engine in summer the radiator shutters were removed and replaced by a large chicken wire grille and sometimes even a few of the air-filters were removed. The photo of 3150 and a sister unit at London on 20 May 1972 shows the unit on the right with the standard radiator shutters and the unit on the left with the special summer grille.


Two units (3151, 3153) lost their electrical generator equipment after wrecks and were reclassified MR-18g. The equipment was re-installed in two baggage cars that became EGUs 15300 and 15301. The MR-18gs powered Tempo trains with either another MRE-18g or EGUs 15300-15302. The short hood was rebuilt with only a few louvers and the roof vents were modified as seen in the photos of 3151 at Komoka on 14 June 1972 and at London on 29 December 1971 (opposite side) and of the roof of 3153 at London on 12 July 1981 (note also louvers on short hood)

CN 3151 CN 3151 CN 3153

By 1983 all Tempo units were retired.