Illinois Central 2-8-4 "Berkshire" Type Locomotives

Introduction

The Illinois Central Railroad bought fifty "Berkshire" type locomotives from the Lima Locomotive Works in 1926. They were designated as Class A-1 and numbered 7000 through 7049. Numbers 7000 through 7039 had Elesco feed water heaters and numbers 7040 through 7049 had Worthington BL feed water heaters. The IC then purchased the Lima A-1 demonstrator and numbered it 7050. This is the very same demonstrator that was tested in the Berkshire Hills for the Boston & Albany and later went on the road to sell this new class of locomotive for Lima.

These superpower locomotives designed and tested for rugged mountainous service on heavy grades were used on a nearly flat division of the Illinois Central. These locomotives had 63 1/2" diameter drivers, except number 7050 had 63" diameter drivers, 28" x 30" cylinders, a boiler pressure of 240 psi with a resultant tractive effort of 68,850 pounds (69,400 pounds for number 7050). Each weighed 388,000 pounds except number 7050 weighed 385,000 pounds. These Class A-1 locomotives provided the inspiration for the Paducah sandbox on the number 2500 through 2600 4-8-2s and later versions of locomotives in the fleet.

As the Paducah, KY shops embarked on the rebuilding program in 1937, they converted #7038 into a 4-6-4 Hudson with the intent to convert all 2-8-4s to this wheel arrangement for use in high speed merchandise freight service. This locomotive was numbered 1 until 1945 when it was renumbered 2499. It was scrapped in 1950. As this was one of the few failures from Paducah they upgraded the remaining locomotives as 2-8-4s and renumbered them 8000 through 8049. The IC called them "Limas", but the enginemen called them "Big Mikes". These 2-8-4s lost their most Lima-distinguishing characteristic, the feed water heater that hung over the brow of the smoke box door. With this change and some others these locomotives assumed the standardized look and design of Illinois Central motive power.

The rebuilds provided the railroad with locomotives that weighed 393,000 lbs and had 63 1/2" diameter drivers, 27" x 30" cylinders and exerted 77,578 pounds of tractive effort under 265 psi of boiler pressure.

There are no surviving IC 2-8-4 "Berkshire" type locomotives

Roster by Richard Duley

ClassQty.Road NumbersYear BuiltBuilderNotes
A-1507000-70491926LimaNumbers 7000-7049 scrapped between 1948 and 1956
A-1 170501925LimaNumber 7050 scrapped by 1956

Class Details by Steve Llanso

Class 7000 (Locobase 48)

Data from table in 1930 Locomotive Cyclopedia and IC 9 - 1928 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive collection. Works numbers were 7136-7160 in November 1926, 7161-7185 in December 1926.

The first 40 engines had Elesco feedwater heater, the last 20 used Worthingtons. Valve motion had limited cutoff, piston valves measured 14" (356 mm) in diameter. The very first 2-8-4 was originally built as a demonstrator locomotive, then sold to the IC. Boston and Albany A1 (Locobase 46) and Boston and Maine T-1s (Locobase 47) were very similar.

Drury (1993) says these engines "rode poorly above 40 mph, sometimes so roughly that the reverse gear wheel would suddenly spin into full forward gear. When that happened the throttle had to be closed at once and the valve gear returned to the proper position -- and several engineers broke an arm doing so." (203) The trailing truck also had a tendency to derail when backing up.

A thorough rebuilding in 1939 made major changes to the engines; see Locobase 15624"

Class 7000 - mod with circulators (Locobase 15624)

Data from table in 1930 Locomotive Cyclopedia and IC 1955 Locomotive Diagrams supplied in August 2013 by Allen Stanley from his extensive collection.

As noted way back in Locobase 49, these 2-8-4s were not completely satisfactory as delivered. The IC's Paducah shops oversaw perhaps the most extensive rebuilding program of any railroad, reworking hundreds of locomotives to address shortcomings or meet new needs.

So it was with the 7000s. Modifications undertaken in 1939 reduced cylinder size by an inch to 27" (686 mm) while retaining the 14" (356 mm) piston valves. The boiler's layout abandoned the Type E superheater and substituted the older, but more easily maintained Type A. Apparent superheater area dropped by 36%, but the ratio to combined heating surface area remained relatively high. To compensate for the smaller cylinder volume, the the IC raised the BP setting to 265 psi (18.25 bar). The trailing truck's booster was also removed.

Most of the class retained the thermic syphons in their fireboxes. Some of the class had their fireboxes refitted with five circulators offering 109 sq ft (10.1 sq m) of heating surface area. Direct heating surface area fell slightly to 389.4 sq ft (36.5 sq m). Locobase shows that version in the specifications accompanying this entry. Still others dispensed with syphons or circulators and included only 53.4 sq ft (4.95 sq m) of arch tubes; these had a total evaporative heating surface area of 4,709 sq ft (437.5 sq m).

Weight distribution between the drivers and the trucks changed considerably, most likely to relieve the trailing truck of some of its considerable burden. So while adhesive weight increased by 23,400 lb (10,614 kg), overall engine weight grew by only 5,500 lb (2,495 kg). Tender capacity grew by four tons of coal, but water capacity remained the same.

One of the class -- 7038 -- was rebuilt in 1936 as a 4-6-4; see Locobase 1357."


Specifications by Steve Llanso
Class70007000 - mod with circulators
Locobase ID48 15624
RailroadIllinois Central (IC)Illinois Central (IC)
Whyte2-8-42-8-4
Road Numbers7000-70497000-7049 / 8000-8049
GaugeStdStd
BuilderLimaIC
Year19261939
Valve GearBakerBaker
Locomotive Length and Weight
Driver Wheelbase16.50'16.50'
Engine Wheelbase41.67'41.67'
Ratio of driving wheelbase to overall engine wheebase 0.40 0.40
Overall Wheelbase (engine & tender)82.48'83.19'
Axle Loading (Maximum Weight per Axle)62200 lbs
Weight on Drivers248000 lbs271400 lbs
Engine Weight388000 lbs393500 lbs
Tender Light Weight286000 lbs295000 lbs
Total Engine and Tender Weight674000 lbs688500 lbs
Tender Water Capacity15000 gals15000 gals
Tender Fuel Capacity (oil/coal)20 tons24 tons
Minimum weight of rail (calculated) on which locomotive could run103 lb/yard113 lb/yard
Geometry Relating to Tractive Effort
Driver Diameter63"63"
Boiler Pressure240 psi265 psi
Cylinders (dia x stroke)28" x 30"27" x 30"
Tractive Effort76160 lbs78194 lbs
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.26 3.47
Heating Ability
Firebox Area414 sq. ft389.40 sq. ft
Grate Area100 sq. ft100 sq. ft
Evaporative Heating Surface5164 sq. ft4761 sq. ft
Superheating Surface2111 sq. ft1355 sq. ft
Combined Heating Surface7275 sq. ft6116 sq. ft
Evaporative Heating Surface/Cylinder Volume241.53239.48
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2400026500
Same as above plus superheater percentage3096032330
Same as above but substitute firebox area for grate area128174125893
Power L13092026457
Power MT1099.47859.66

Photos

Reference

Credits

Introduction and roster provided by Richard Duley. Class details and specifications provided by Steve Llanso of Sweat House Media.