ALCO HH series


The ALCO HH series were an early series of switcher diesel-electric locomotives built by the American Locomotive Company of Schenectady, New York between 1931 and 1940, when they were replaced by the S series; the S-1 and S-2. They were ALCO's first diesel switchers to enter true series production, and among the very first land vehicles anywhere to use the revolutionary diesel-electric power transmission.
The "HH" name stood for "High Hood", a name ALCO came eventually to use in an official context, but originally an unofficial name. Model designations such as HH600 are only semi-official. Original ALCO designations were either descriptive or based on the internal order/design number.
A total of 177 of the HH series were produced; this comprised one prototype and four production models of varying power outputs.

ALCO 600 (New Haven #0900)

The first HH series locomotive, ALCO demonstrator #600 was mechanically almost identical to the others, but the appearance differed. The sides of the locomotive's hood sloped outward from top to bottom, and brake equipment was exposed beneath the cab. After a period of demonstration on a number of railroads, the unit was sold to the New York, New Haven and Hartford Railroad who numbered it as 0900, this number often being used to describe the locomotive, although the classification on the builder's data card was "404-OE-200". It rode on a unique pattern of trucks. This first unit was built in July 1931.

Diesel-electric power transmission

The locomotive was equipped with a four-stroke McIntosh & Seymour 531 straight-6 diesel engine, powering a General Electric GT551A1 main generator. Four nose-suspended GE-287-D traction motors in the trucks were geared at a ratio of 4.25:1 to the wheels; the motors were cooled by electrically driven traction motor blowers.
File:wikiBC43big.jpg|thumb|Buffalo Creek #43 HH660 owned and operated by the . 2018 photo.

HH600

The HH600 was nearly identical to the previous #0900 of the New Haven internally and mechanically, but it was clad in new bodywork, with a straight-sided hood and cab sides that came all the way to the frame. The HH600 was powered by a 6-cylinder McIntosh & Seymour 531 engine of, and was built from July 1932 through May 1939; in all, 78 HH600s were constructed. The first-built units had sharp-edged front hood corners, but in 1934 ALCO employed industrial designer Otto Kuhler to clean up the appearance; he curved the corners and recessed the headlight, and all subsequent HH series units were of this style until another restyling in 1938 where the nose was further rounded. Late versions of this locomotive used the 6-cylinder 538 engine.

Original buyers

HH900

The HH900 was a 900 hp version of the HH series using a turbocharged version of the McIntosh & Seymour 531 engine. Both turbocharged models needed a greater cooling capacity, and this was reflected in the larger bodyside radiator space of both models, which distinguishes them from the lower-powered HH600 and HH660. The 21 HH900 units were produced between March 1937 and January 1939, after which it was replaced by the McIntosh & Seymour 538T-engined HH1000. Several HH900s were built with the 538T engine.

Original buyers

RailroadQuantityRoad numbersNotes
American Locomotive Company
1
101
to CRI&P 730
Birmingham Southern Railroad
8
81–88
Elgin, Joliet and Eastern Railway
1
402
Kansas City Terminal Railway
1
50
Minnesota Transfer Railway
3
90–92
Philadelphia, Bethlehem and New England Railroad
1
207
to South Buffalo Railway 70
Reading Company
2
40–41
Warrior River Terminal Company
2
50–51
Youngstown and Northern Railroad
2
211–212
Total21

HH660

The HH660 started production in ALCO's lineup in October 1938; 43 examples were built until April 1940. It used a naturally aspirated version of the 6-cylinder McIntosh and Seymour 538 engine, producing. Externally, HH660s are indistinguishable from late HH600s.

Original buyers

RailroadQuantityRoad numbersNotes-
American Locomotive Company
1
4
-
Atlantic Coast Line Railroad
1
1900
-
Boston and Maine Railroad
1
1162
-
Buffalo Creek Railroad
1
43
To ' - 1966, to ' - 2000
Chicago, Milwaukee, St. Paul and Pacific Railroad
4
1600–1603
Renumbered 980–983
-
Delaware, Lackawanna and Western Railroad
3
409–411
409–410 to Erie-Lackawanna Railway 324–325-
Elgin, Joliet and Eastern Railway
3
210–212
211 to Gopher State Scrap and Metal-
Erie Railroad
4
302–305
305 to Erie-Lackawanna Railway-
Green Bay and Western Railroad
1
101
-
Inland Steel
1
50
-
Louisville and Nashville Railroad
1
10
-
Maine Central Railroad
2
951–952
-
Minneapolis and St. Louis Railway
1
D939
To Glacier Sand & Gravel-
New York, New Haven and Hartford Railroad
10
0921–0930
-
Northern Pacific Railway
3
125–127
125–126 to Walla Walla Valley Railway 770, 775;
  • 127 renumbered 602.
  • 770 to Relco 770
  • to Port of Longview 770 Longview, Wa to Jeff Davis of Longview Wa.
    		• -
    Southern Pacific Company
    3
    1001–1003
    		--
    Tennessee Central Railway
    1
    50
    		-
    Wabash Railroad
    2
    100, 150
    		-
    Total43-

    HH1000

    The HH1000 replaced the HH900, replacing the 531 engine with the new McIntosh and Seymour 538T engine, turbocharged to produce 1000 hp, a 100 hp increase on the previous model. It was produced during May 1939 and December 1940; 34 were built.
    M&STL D539 was the only HH1000 built with the 531T engine.

    Original buyers

    RailroadQuantityRoad numbersNotes
    American Locomotive Company
    1
    1000
    Atchison, Topeka and Santa Fe Railway
    12
    2310–2321
    Atlantic Coast Line Railroad
    1
    600
    Birmingham Southern Railroad
    1
    89
    Chicago, Milwaukee, St. Paul and Pacific Railroad
    1
    1671
    Manufacturers Railway
    3
    202–203
    Michigan Limestone and Chemical Company
    4
    103–106
    Minneapolis and St. Louis Railway
    1
    D-539
    		Renumbered 92; to Chicago and North Western Railway
    Missouri Pacific Railroad
    1
    9102
    Newburgh and South Shore Railway
    2
    1–2
    Oliver Iron Mining Company
    7
    900–906
    Total34

    Specifications

    Surviving units

    A few HH series switchers still survive in revenue service, and more are in museums. Working HH locomotives include an HH660 at Gopher Scrap in Mankato, Minnesota, one more owned by the , and one owned by Behr Iron and Steel of Portage, Indiana. Preserved locomotives include an HH600, four HH660s, an HH900 and an HH1000.