The Chicago and North Western R-1 class is a class of 325 4-6-0 "Ten-Wheeler" steam locomotives built by the Schenectady Locomotive Works, the American Locomotive Company, and the Baldwin Locomotive Works from 1901 to 1908. The R-1 locomotives were so large and heavy that the Chicago and North Western (C&NW) Railroad had to extensively rebuild their trackage, bridges, tunnels, turntables, and enginehouses to accommodate them.
The R-1s were widely considered to be one of the most reliable classes of locomotives on the C&NW's roster. They were able to travel all across the C&NW system by the 1940s, and they received varying modifications, including superheater installations and conversions to burn oil. The R-1 class also served as the basis for the Chicago, St. Paul, Minneapolis and Omaha (CMO) Railway's I-1 and K-1 classes. As of 2026, only three R-1 locomotives are preserved; two are undergoing restoration to operating condition, while one remains on static display.
History
Development After the year 1900, railroad traffic in the United States was constantly growing, and existing locomotive rosters and rail infrastructures were becoming inadequate. By that time, the Chicago and North Western Railroad (C&NW) experimented with various firebox designs on steam locomotives to meet the demand for greater motive power. They rostered 250 4-6-0 "ten-wheeler" locomotives that were divided into seven classes, including the R class locomotives built between 1897 and 1900, and they all came with larger fireboxes that were placed above the frame, as opposed to in between the frame and the wheels. This allowed for a larger grate area and a larger fire.
In 1899, the C&NW created a new boiler design with a wide firebox, long boiler tubes, and a boiler pressure. The following year, this boiler design was applied to the first of the railroad's D class 4-4-2 "Atlantic" type locomotives. With the D class 4-4-2s earning recognition for their good performance, a freight locomotive design with the new boiler was being developed.
Design and construction
The new locomotive design was destined to be an upgrade to the R class, with its classification name being the R-1. The R-1 design was to be equipped with diameter driving wheels, and the boiler and firebox were to be lifted and carried over the driving wheels. The rear section of the R-1 boiler with the firebox was to be larger than that of the D class at in diameter, while the front section of the boiler was to be smaller at . The cylinders were to be in diameter, making the cylinders the largest to ever be applied to a C&NW locomotive at the time.
On January 1, 1901, the C&NW placed their first order of twenty R-1 locomotives to be built by the Schenectady Locomotive Works (SLW). Additional orders of R-1s would be made, following SLW's merger into the American Locomotive Company (ALCO). Aside from the new boiler design, a new valve design, larger cylinders, and innovative steam generating equipment, the first twenty-seven R-1 locomotives shared identical construction qualities with the R class.
In the fall of 1902, with the availability of technilogical improvements, the C&NW made multiple alterations to the R-1 design; four-bar crosshead guides were replaced with alligator crosshead guides, bolts were replaced with rivets for the boiler, and cast iron was replaced with steel for multiple parts of the locomotive. The alterations added of weight for the locomotive, with the driving wheels bearing a large portion of it. ALCO built and delivered thirty R-1 locomotives with the new alterations in 1902 and 1903, with an additional forty-five being delivered from the Baldwin Locomotive Works (BLW); BLW marked their R-1s as 10-36-D in their classification system.
The first fifty-seven R-1 locomotives were built with tenders that held of water and of coal; they were smaller than the tenders of the R class. The tenders were built at a smaller scale, because most C&NW turntables at the time were found to be too short to fit an R-1 with a longer tender. BLW's forty-five R-1s from 1903 were built with tenders that held of water and the same coal capacity as the older tender design. Beginning in 1905, the rest of the R-1 locomotives were built with larger tenders that held of water and of coal.
In September 1904, the C&NW asked ALCO to construct one D class 4-4-2 (No. 1300) and one R-1 class 4-6-0 (No. 76) with superheated boilers. After they entered service, the C&NW became unsatisfied with their performance, and no further Ds or R-1s were built new with superheaters.
Most R-1 locomotives were applied with Stephenson valve gear, but the increased size of the axles and strength requirements resulted in greater wear and tear on the Stephenson eccentric rods on the R-1's running gear, despite the later locomotives being built with improved metal. At the same time, Walschaerts valve gear was becoming available on American steam locomotive technology. In early 1907, the C&NW placed an order of thirty R-1s from ALCO, and in doing so, they asked for five of the locomotives (Nos. 1393–1397) to be applied with Walschaerts valve gear for testing.
While the Walschaerts application made the five locomotives several thousand pounds (kg) heavier than any Stephenson-powered R-1, their performance was deemed a success. The C&NW subsequently asked BLW and ALCO to build and deliver thirty-five (ten from BLW; twenty-five from ALCO) additional Walschaerts-powered R-1s throughout 1908. By the time production on the R-1 class ended in December 1908, 325 locomotives of the class were built, making the R-1s the most manufactured class of steam locomotives on the C&NW. + Table of orders and numbers Year Quantity Manufacturer Serial numbers C&NW numbers Notes 1901 16 Schenectady 5844–5859 168/78, 287/89–91/95, 896, 910–12/22/39, 1041/42 1901 4 Schenectady 6206–6209 160, 594–596 1902 14 Alco 25397–25410 1066–1079 1902 9 Alco 26530–26538 1102–1110 1903 14 Alco 27581–27594 1111–1124 1903 45 Baldwin 22509/19/39/40/63/67/68/76,22624/25, 22701/18/58/65/73/80,22818/24/35/43/61/64/86, 22909/35/36/50/71/94, 23004/25/32/67/68/83/84/94,23102/16/17/25/34/55/84, 23217 1125–1169 1905 18 Alco 30299–30316 76, 416/41/51/54/66/78/76/81/83, 236/37, 479, 916/17, 462/63 1905 15 Alco 30595–30609 469–474/80/84–91 1906 30 Alco 38513–38542 411–14/17/18/22–25/29/40/42/44–49, 899, 915/23/24, 1219–1222/29–31 1906 35 Alco 39212–39246 1333–1367 1907 30 Baldwin 31547–49/59–62/85–88, 31618–23/73/87/88, 31734/45–47/84, 31830/55/56/84, 31914 18, 29, 38, 44, 50, 61, 62, 122/59/61/82/84/85, 245, 343–45/48/49/59/60, 452, 555, 925/34–38/60 1907 30 Alco 42170–42199 1368–1397 1907 30 Alco 42399–42428 1398–1427 1908 10 Baldwin 32567/74/94, 32602–04/26/45/60/61 1323–1332 1908 25 Alco 45726–45750 172/75, 375–80/82/83/85/86/88, 406/50/53/55–58, 893/94, 926/27/52
Service The R-1 locomotives were primarily designed as dual-service locomotives to pull both passenger and freight trains. Because the R-1s were larger and heavier than any other C&NW locomotive before them, their route availability was drastically limited, so the C&NW initiated a program to upgrade their entire rail infrastructure to accommodate them. The railroad rebuilt several miles of trackage and bridges with enough heavy weight to support an R-1. Existing roundhouse stalls proved to be too short for the R-1s to fit inside, so some of them were extended to allow the R-1s to be serviced indoors, and bigger roundhouses and terminals were eventually constructed to allow room for larger locomotives.
By the end of 1902, the R-1s were allowed to operate on certain routes on the Wisconsin Division, but they were restricted from running anywhere on the Iowa and Minnesota divisions until 1910. By the 1920s, the C&NW had completed many miles of track upgrades for use by the R-1s and other large locomotives, but the R-1s were still restricted from running on certain branchlines, due to short, light-weight turntables; some turntables were replaced with extended wye tracks for easier turning. By 1939, the R-1's limited route availabilities were lifted, and they were permitted to travel anywhere on the C&NW system, when necessary.
When steam-heated passenger cars became common on branch lines, several of the R-1s could not pull passenger trains, due to their lack of steam-heating equipment. All forty Walschaerts-powered R-1s were built with steam-heating and air signal line equipment, so they were assigned to passenger service for most of their working spans. Some R-1s were also used to pull the C&NW's Flambeau 400 connection trains between Watersmeet, Michigan and Monico, Wisconsin. While the C&NW acquired larger locomotives after 1908, such as the Z class 2-8-0 "Consolidations" from 1909, the J class 2-8-2 "Mikados" from 1913, and the H class 4-8-4 "Northerns" from 1929, none of them could replace the R-1s on many of the railroad's routes, due to weight restrictions. After 1920, the R-1s were primarily relegated to branch line services, but they were still occasionally used to pull mainline trains and for switching services.
Modifications After testing five E class locomotives in 1910, the C&NW decided that superheated technology had improved for steam locomotives, so they began to modify their existing steam fleet with superheated boilers, with the R-1s receiving superheaters beginning in 1915. By the 1930s, most R-1 locomotives were equipped with superheaters. Also in 1915, the railroad made plans to rebuild some of the R-1s with larger cylindrical boilers, with the front section to be in diameter. Despite the intervention from World War I and the United States Railroad Administration (USRA), the C&NW moved forward with the cylindrical boiler installations, with the process beginning in 1922.
Beginning in 1911, the C&NW converted a number of their R-1 locomotives from coal-firing to oil-firing, to allow them to operate west of the Missouri River. At least eighty-seven locomotives were known to have been converted to burn oil at some point in their working spans. While the R-1s received many other varying modifications during their working spans, none of the Stephenson-powered R-1s were rebuilt with Walschaerts valve gear, and only one locomotive with four-bar crosshead guides was ever rebuilt with alligator crosshead guides.
Withdrawal The first R-1 to be retired was No. 1132; it was scrapped in 1929, following a 1926 boiler explosion. Most of the other R-1s lasted more than fifty-five years in service. The R-1 locomotives' wide route availabilities resulted in more than 190 of them to remain in active service by 1952. By the time the C&NW discontinued their commercial steam operations in 1956, more than seventy R-1s had been kept in service, before they were all retired. Some R-1s, such as Nos. 1329 and 175, were painted with white trim stripes for use in pulling occasional excursion fantrips throughout the 1950s, prior to their retirement.
+ Table of pre-1948 scrappings Year Quantity inservice atstart of year Quantityscrapped Numbers Notes 1929 325 1 1132 1936 324 4 476, 1130/61, 1359 1937 320 6 184, 360, 1102/11/31/67 1938 314 1 893 1939 313 12 168, 382, 425/49/83, 1077, 1110/12/16/63, 1229, 1395 1940 301 26 245, 375/80, 417/23/51/71/91, 960, 1120/36/38/45/64/66,1336/45/47–49/57/69/75/93/99, 1421 1941 275 7 185, 424, 896, 1219, 1334/64/67 1942 268 1 1392 1943 267 3 1137, 1382, 1420 1944 264 19 418/47/80, 1041/42/74, 1104/14/39/41/43, 1328/35/61/63/65/97, 1411/24 1945 245 7 182, 921, 1126, 1339/51/70, 1416 1946 238 7 290, 452/66, 915, 1106/47, 1405 1947 231 18 44, 61, 122, 295, 343, 484/85, 596, 1070/76/78, 1105/50, 1327/33/55/88/91 1948 213 1 1406 First half-year only
Preservation Out of the 325 R-1 locomotives that were built, only three have been preserved. Two of the R-1s, Nos. 175 and 1385, are currently undergoing restoration to operating condition, whereas one, No. 444, remains on static display.