Monon Diesel Roster (All-Time)

Published: October 28, 2026

The Monon dieselized earlier than a railroad of its size had any right to, and then spent the rest of its life learning what would fit the railroad it actually had. Street running, sharp curves, and rail that was never meant for a six-axle Century set the limit. The all-time list counts 96 locomotives, each frame once. A renumbering is the same locomotive. The two cabs and the booster wrecked at Ash Grove in 1947 are counted, and so are the three new units that replaced them. The 57 diesels in the 1951 glance are that year’s fleet, not this total. The company history is a separate page. The steam roster is another.

New Monon F3As in a builder photograph, January 1947

An Electro-Motive photograph of new Monon F3As in January 1947. On this railroad the A and B suffixes were both cabs. The C suffix was the booster.

On this page: At a glance · Switchers · The F3s · BL2s and road switchers · Centuries and the U23Bs · Roster

At a glance

Item	Detail
Railroad	Chicago, Indianapolis & Louisville, later the Monon Railroad. Company history
This table	Diesels the railroad owned. Each frame once
Electro-Motive	49. Three SW1s, seven NW2s, nine BL2s, 24 F3A cabs, six F3B boosters
American Locomotive	36. Nine RS-2s, nine C628s, 18 C420s
General Electric	8. U23Bs 601–608, the last new freight power
Fairbanks-Morse	3. One H10-44 and two H15-44s
Quantity column	96
1951 fleet	57. A year count, after the Ash Grove wrecks and the sale of the first SW1
First diesels	SW1 DS-50 and three NW2s, 1942
Last new passenger power	C420s 501–502, August 1966, high short hood and a steam generator

Switchers

The first diesel was a 600-horsepower SW1, DS-50, in February 1942, later numbered 1. It was sold to United Electric Coal in 1947 and is preserved at the Hoosier Valley Railroad Museum. Two more SW1s, 5 and 6, arrived in August 1949. The three NW2s of April 1942, DS-1 through DS-3, became 11, 12, and 13. Four more NW2s, 14–17, came in January 1947. No. 11 was sold to the Elgin, Joliet & Eastern. No. 14 followed in 1970. Nos. 12, 13, and 15–17 passed to the Louisville & Nashville.

Fairbanks-Morse contributed three switchers and then stopped. H10-44 No. 18, November 1946, went to W. R. Grace in 1963. The two H15-44s were built in September and December 1947 as 36 and 37 and were renumbered 45 and 46 in 1949, which cleared 36 and 37 for the last BL2s. Both were re-engined with EMD 567s in July 1960. They were the same two locomotives, and they are counted once.

The F3s

The road freight and passenger fleet began with F3s. On the Monon an A or a B after the number meant a cab. A C meant the booster. That is the opposite of the habit on many other railroads, where B was the booster and C was the second cab. The first cabs were 51A, 51B, 52A, and 52B in December 1946, and 61A through 64B from December 1946 into January 1947. Eight more cabs, 81A through 84B, arrived in May 1947 to lead the rebuilt Army hospital cars. Two further cabs, 85A and 85B, were EMD demonstrators 754A1 and 754A2, built in September 1946 and bought for the Monon. The boosters were 61C through 64C, new, plus 65C, former demonstrator 754B1, built in July 1945.

Monon F3A 203, formerly 82A, at Hammond, Indiana, on October 13, 1963

F3A 203, formerly 82A, at Hammond, Indiana, on October 13, 1963. The 81–84 series later carried 201–208. American-Rails.com collection.

On June 3, 1947, a collision at Ash Grove, near the Lafayette shops, wrecked cabs 62B and 64A and booster 64C. Those three frames stay in the count. Two new cabs, the second 62B and the second 64A, replaced the wrecked cabs in April 1948 and later became 106 and 109. A new booster, the second 64C, arrived in October 1947 and later became 304. A few numbers were passed around in the meantime. Original 51A wore 64A for a year and then went back, and original 64B spent time as 62B and as 51B. Those were the same locomotives, not extra ones. In the later three-digit scheme the 100s were the early cabs, the 200s were the 81–85 series, and the 300s were the boosters.

BL2s and road switchers

Nine BL2s, 30–38, gave the Monon the largest fleet of that odd EMD road switcher. Four, 30–33, and two more, 34 and 35, came in April 1948 on the same order with two blocks of serials. The last three, 36–38, came in May 1949. No. 32 is at the Kentucky Railway Museum. The nine RS-2s, 21–29, were built from January through October 1947, rebuilt to 1,600 horsepower in 1963 and 1964, and renumbered 51–59 in 1965 and 1966. They went to the Louisville & Nashville as 260–268.

Monon RS-2 53 outside the Lafayette shop in September 1971

RS-2 53 outside the shop in Lafayette, Indiana, in September 1971, still in Monon paint after the Louisville & Nashville merger. It had been No. 23. Warren Calloway photo.

Centuries and the U23Bs

The six-axle experiment was nine C628s, 400–408, in March 1964. They were bought for a unit-coal move from the Ohio River to Michigan City. The Interstate Commerce Commission refused the plan. The locomotives were too long in the wheelbase for the curves and heavy enough to spread the rail, which is about what a 475,000-pound steam engine would have done on the same railroad thirty-five years earlier. They went back to Alco in 1967 and became Lehigh Valley 633–641.

Monon C628s 404 and 407 at New Albany, Indiana, on June 26, 1964

C628s 404 and 407, nearly new, at New Albany, Indiana, on June 26, 1964. David Hawkins collection.

Three nearly new Monon C628s at New Albany, Indiana, on June 26, 1964

Three of the C628s, nearly new, at New Albany on the same day. When the coal trains were refused, the nine went back to Alco and on to the Lehigh Valley. David Hawkins collection.

Monon C628 402 at the Hammond yard on March 31, 1964

C628 402 at the yard in Hammond, Indiana, on March 31, 1964. Roger Puta photo.

Two Monon C628s and an RS-2 at Bloomington, Indiana, on April 16, 1966

Two C628s and an RS-2 on a mixed freight at Bloomington, Indiana, on April 16, 1966. Keith Ardinger photo. Warren Calloway collection.

What replaced them was the C420, eighteen four-axle units. Nos. 501 and 502, August 1966, were the high-short-hood passenger pair, with a steam generator in the nose. They were the last new passenger locomotives the Monon bought, and among the last anyone bought. Nos. 503–506 came the same month, in the low-hood freight version. Nos. 507–518 followed in August 1967. All eighteen went to the Louisville & Nashville, 1318–1335.

Builder photograph of Monon C420 505 at Schenectady in August 1966

C420 505, new at Schenectady, New York, in August 1966. American Locomotive builder’s photograph.

Monon C420s at Lafayette, Indiana, in September 1971

C420s at Lafayette, Indiana, in September 1971. Warren Calloway photo.

The last new freight locomotives were eight General Electric U23Bs, 601–608, in March and April 1970. They became Louisville & Nashville 2700–2707 and, much later, CSX 3230–3237. They are the same eight frames. The one electric, McGuire-Cummings No. 5 of 1915, is not in this 96. It is on the company page.

Roster

Model	Road Number	Qty	Date	Builder Number	Order	Notes
SW1	DS-50	1	2/1942	1597	E460	Later 1. Sold in 1947
SW1	5–6	2	8/1949	8423–8424	E1254
NW2	DS-1–DS-3	3	4/1942	1598–1600	E461	Later 11–13. 11 sold to the Elgin, Joliet & Eastern. 12 and 13 to L&N 2202 and 2203
NW2	14–17	4	1/1947	4445–4448	E794	14 sold to the Elgin, Joliet & Eastern. 15–17 to L&N 2205–2207
BL2	30–33	4	4/1948	4449–4452	E975	32 is at the Kentucky Railway Museum
BL2	34–35	2	4/1948	5243–5244	E975
BL2	36–38	3	5/1949	8420–8422	E1253
F3A	51A, 51B, 52A, 52B	4	12/1946	3663–3666	E703A	Cabs. Later 101, 110, 111, and 112
F3A	61A–64A, 61B–64B	8	12/1946–1/1947	3669–3676	E704A	Cabs. 62B and 64A wrecked at Ash Grove, June 3, 1947
F3A	62B (2nd), 64A (2nd)	2	4/1948	7416–7417	E1055A	New cabs, replacing the wrecked pair. Later 106 and 109
F3A	81A–84A, 81B–84B	8	5/1947	4453–4460	E796A	Cabs for the rebuilt passenger cars. Later 201–208. 82A became 203
F3A	85A, 85B	2	9/1946	—	—	Cabs. Ex-EMD demonstrators 754A1 and 754A2. Later 209 and 210
F3B	61C–62C	2	12/1946	3677–3678	E704B	Boosters. Later 301 and 302
F3B	63C–64C	2	1/1947	4067–4068	E704B	Boosters. 64C wrecked at Ash Grove. 63C later 303
F3B	64C (2nd)	1	10/1947	5194	E878B	Replacement booster. Later 304
F3B	65C	1	7/1945	—	—	Booster. Ex-EMD demonstrator 754B1. Later 305
H10-44	18	1	11/1946	—	—	Sold in 1963
H15-44	36–37	2	9/1947–12/1947	—	—	Later 45 and 46. Re-engined with EMD 567s in July 1960. Same frames
RS-2	21–29	9	1/1947–10/1947	—	—	Later 51–59. Rebuilt to 1,600 horsepower, 1963–64. To L&N 260–268
C628	400–408	9	3/1964	—	—	Returned to Alco in 1967. Lehigh Valley 633–641
C420	501–502	2	8/1966	—	—	High short hood, steam generator. To L&N 1318–1319
C420	503–506	4	8/1966	—	—	To L&N 1320–1323
C420	507–518	12	8/1967	—	—	To L&N 1324–1335
U23B	601–608	8	3/1970–4/1970	—	—	Later L&N 2700–2707, then CSX 3230–3237

Sources

Gary W. Dolzall and Stephen F. Dolzall, Monon: The Hoosier Line. Road numbers, later numbers, and dispositions, including the roster circulated by the Monon Railroad Historical-Technical Society.
Electro-Motive order numbers and serials for the locomotives on the CI&L production list at trainweb.us/emdloco/cil.htm. Demonstrator cabs 85A and 85B, and booster 65C, are not on that list.

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