ALCO HH series

Infobox Locomotive
name=ALCO HH series
powertype=Diesel-electric

---

caption=Portland Terminal Company HH600 #1002, photographed at Portland, Maine on August 16, 1937.
gauge=RailGauge|ussg
builder=ALCO
wheeldiameter=convert|40|in|m|3|abbr=on
primemover=HH600/900: McIntosh and Seymour 531;
HH660/1000: McIntosh and Seymour 538
enginetype=Four-stroke diesel
aspiration=HH600/660: Naturally aspirated;
HH900/1000: Turbocharged
cylindercount=Inline-6
cylindersize=convert|12.5|x|13|in|mm|0|abbr=on
displacement=convert|9572|cuin|L|abbr=on
length=convert|45|ft|2+3/4|in|m|2|abbr=on
poweroutput=convert|600|hp|kW|0|abbr=on,
convert|660|hp|kW|0|abbr=on,
convert|900|hp|kW|0|abbr=on, or
convert|1000|hp|kW|0|abbr=on
aarwheels=B-B
builddate=
totalproduction=HH600: 79;
HH660: 43 ;
HH900: 21;
HH1000: 34

The ALCO HH series were an early series of switcher diesel-electric locomotives built by the American Locomotive Company (ALCO) of Schenectady, New York between 1931 and 1940, when they were replaced by the S series; the convert|660|hp|abbr=on S-1 and convert|1000|hp|abbr=on S-2. They were ALCO's first diesel switchers to enter true series production, and among the very first land vehicles anywhere to utilise 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 and Seymour Model 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. [cite web|url=http://www.northeast.railfan.net/images/alco600a.jpg|title=ALCO 600 build sheet]

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 and Seymour 531 engine of convert|600|hp|abbr=on, 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

HH1000

The HH1000 replaced the HH900, replacing the 531 engine with the new McIntosh and Seymour 538T engine, turbocharged to produce 1000 hp (750 kW), a 100 hp (75 kW) 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

Specifications

urviving 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, two more owned by RELCO, and one owned by Behr Iron and Steel of Portage, Indiana. Preserved locomotives include an HH600, four HH660s, an HH900 and an HH1000.

Notes

References

*
* Sweetland, David. (2004) "Santa Fe's Alco Switcher Fleet". Diesel Era Vol. 15 No. 6, November/December 2004, pp. 10-31. Withers Publishing, Halifax, Pennsylvania.
* Laundry, Mark. " [http://yardlimit.railfan.net/alco/hh/index.html Alco High Hood Models] ". Retrieved March 29, 2005.
* Komaneski, John. " [http://www.thedieselshop.us/Alco_HH600.HTML ALCO HH600 Roster] ". Retrieved March 27, 2005. States information originally from Extra 2200 South.
* Komaneski, John. " [http://www.thedieselshop.us/Alco_HH660.HTML ALCO HH660 Roster] ". Retrieved March 27, 2005. States information originally from Extra 2200 South.
* Komaneski, John. " [http://www.thedieselshop.us/Alco_HH900.HTML ALCO HH900 and HH1000 Roster] ". Retrieved March 27, 2005. States information originally from Extra 2200 South.
** Data sheets: [http://www.thedieselshop.us/DataHH600.HTML HH-600] , [http://www.thedieselshop.us/DataHH660.HTML HH-660]
* Steinbrenner, Richard (2003) The American Locomotive Company A Centennial Remembrance. Chapter VI subchapter "ALCO's First Production Diesels".