Significance: "The Georgetown Steam Plant is an early reinforced concrete structure housing America's last operable examples of the "first generation" of large scale, vertical steam turbine electric generators, It is also significant as an early example of "fast track" construction advocated by Frank B. Gilbreath." The plant was built with two vertical Curtis turbine units: 3mw and 8mw. A 10mw horizontal Curtis turbine was added in 1917. When the airport was constructed next to it in the 1930's, the smokestacks were removed and replaced by fans to induce the draft. The plant was built on the east bank of the Duwamish River. But the river was moved to make room for the airport. [HAER-data] The second smokestack was concrete and 268' tall with a 17' diameter. [HAER-data, p11] The first stack was steel and 125' tall with an 11' diameter. [HAER-data, p13]
By the late 1920s, hydro power was dominate in this area and the plant provided backup for periods of low water flow. The last production run ended in Jan 1953. Then it ran for tests to keep it qualified as a standby plant. But the test runs ended in the 1970s. [HAER-data, p19-21] After the river was moved, a pump house was built to supply water to the plant. [HAER-data, p75]
It was decommissioned in the 1970s, but has been preserved. There are plans to turn it into a museum and "event space." Currently, it is open once a month for public tours. [CrossCut]
The plant is ASME's Landmark #45.
 |
| HAER WASH,17-SEAT,2--6 6. INTERIOR VIEW LOOKING WEST, SHOWING TURBINES #1 AND #2 (#2 IN FOREGROUND), VACUUM AIR PUMP IS BELOW - Georgetown Steam Plant, South Warsaw Street, King County Airport, Seattle, King County, WA |
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| Street View The short wing that houses the turbine hall. The longer wing that is perpendicular to this wing houses the boilers. |
Dave Fillman posted three photos with the comment: "Curtis vertical steam turbines at the old Georgetown Steam Plant. 2 of 5 left in the world that I know of. They went online in 1906 and 1907 respectively."
 |
| 1 |
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| 2 |
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| 3 |
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| HAER WASH,17-SEAT,2--39 (CT) 39. INTERIOR VIEW, 10,000KW GENERATOR [10mw was the rating of the 1917 horizontal turbine. The vertical turbines were 3mw and 8mw.] |
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| HAER WASH,17-SEAT,2--5 5. INTERIOR VIEW LOOKING EAST, TURBINE #2 WITH BAROMETRIC CONDENSER BEHIND |
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| Georgetown Steam Plant posted In the main room of the Plant, the turbines steal the show — but right behind them stands another, tall actor in the steam powered electrical generating process: The condenser. The steam pushes *to* the turbine through the pressure of its temperature, but to optimize its speed through, it also gets *pulled* by the condenser. The condenser sprays cold water, collapsing the steam and pulling it out of the turbines. This is what the water from the Duwamish River was used for (municipal water was used for the boilers), and it would be returned to the river after the process. The Georgetown Steam Plant is owned by Seattle City Light. Brett Wanamaker shared |
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| HAER WASH,17-SEAT,2--8 8. INTERIOR VIEW, VACUUM AIR PUMP IN FOREGROUND WITH TURBINE #2 BEHIND |
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| HAER WASH,17-SEAT,2--14 14. GENERAL VIEW OF TURBINE #3 |
 |
| HAER WASH,17-SEAT,2--16 16. DETAIL VIEW, STEAM PIPING, LUBE OIL PUMPS AND CONTROLS FOR TURBINE |
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| HAER WASH,17-SEAT,2--20 20. GENERAL VIEW OF MOTOR GENERATOR USED FOR EXCITATION. ORIGINALLY PROVIDED DC POWER TO INTER-URBAN LINES |
And the above excitation generator had its own excitation generator!
 |
| HAER WASH,17-SEAT,2--21 21. GENERAL VIEW OF MOTOR GENERATOR WITH SMALLER GENERATOR IN FOREGROUND TO PROVIDE EXCITATION FOR LARGER DC UNIT |
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| HAER WASH,17-SEAT,2--34 34. VIEW LOOKING NORTH NEAR UNIT #2. MOTOR GENERATOR ON RIGHT AND STEAM EXCITER GENERATOR ON LEFT [I think the caption has left and right reversed. Those pipes on the right look like steam power to me.] |
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| HAER WASH,17-SEAT,2--28 28. GENERAL VIEW LOOKING SOUTH, SHOWING BOILER ROOM |
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| HAER WASH,17-SEAT,2--24 24. ELEVATION OF BOILER. EIGHT INSPECTION DOORS, THREE BURNERS, HEAT SHIELD AT FLOOR, CENTER PRESSURE GAUGE |
This history will be moved to some notes on the Curtis turbine when I get some time to write them.
I. General Electric, Westinghouse and Urban Electrification
In 1882, Thomas Edison opened his Pearl Street Plant in New York City
to initiate the Electrical Age in urban America. While advocates
debated the relative merits of direct and alternating current,
eventually settling on the latter, reciprocating steam engines driving
a separate electrical generator appeared from coast to coast. As
demand for electricity increased, companies tried to increase both the
size and number of generating units, but were beginning to encounter
limits on engine/generator size as well as station size. In an early
attempt to alleviate this threat, the Westinghouse Company secured the
patents to the Parsons steam turbine (patented 1884), the first
successful industrial turbine, much smaller than equal engine/generator
units, even if no more efficient. For nearly a decade, Westinghouse
clearly had the upper hand. The growth of central generating stations
required increases in capacity and the massive engine/generator units
with their vibration limits and size requirements could not meet that
demand. Westinghouse had the only operating turbine on the market.
Charles G. Curtis (1860-1953) received patents 566,967, 566,968, and -
566,969, protecting the basic principles of the Curtis turbine, in
September, 1896. These patents cover, respectively, the expansion
nozzles and their regulation, the concept of velocity compounding, .and
the concept of pressure compounding. Curtis assigned all three patents
to his own company, the Curtis Company, which one year later entered
into a liscensing agreement with the General Electric Company. For
$1,500,000, General Electric received rights to all uses of the Curtis
turbine except aerial and marine propulsion.3.
General Electric formed a hew division to undertake the development and
manufacture of the Curtis turbine. From 1897 to 1902, General Electric
built and tested a variety of designs based on the Curtis patents.
Until 1900, Charles Curtis himself directed this research.2 in 1901,
William Le Roy Errenet took charge of the development of the Curtis
turbine. Eamet (1858-1941), a central figure in General Electric's
development of prime movers, trained at the U.S. Naval Academy and
•worked at various .^obs m the ^lactrteal industry before he joined the
new General Electric in 1892. General Electric, concerned by the lack
of progress with the Curtis turbine project offered Emmet charge of the
turbine project at a point when it was considering dropping it. Emmet
realized the difficulties but thought the work extremely important and
urged that it be allowed to proceed. In his autobiography he noted his
overall impression of the work: "I think it is safe to say that there
have not been many jobs more extensive and strenuous in the art of
engineering." (Emmet 1931, p. 142)
Emmet directed the Curtis turbine project for twelve years, until 1913.
Many of the features of the machine were incorporated as a result of
his guidance, including the vertical orientation of the larger sizes.
Emmet invented the oil-supported step bearing used to test the
generators installed at Niagara Falls and made use of them in the
Curtis turbine. He was also responsible for the selection of the sizes
of the turbine., and for meeting'the deadline'for the delivery of the
first machines. (Enmet 1931, p. 147)
Between 1897 and 1902, General Electric made a number of small turbines
based on Curtis's principles. These were used for tests. The first
placed in operation was a 500 KW unit installed at the General Electric
plant in Schenectady in November, 1901. (Robinson 1937, pp. 239-240)
The first vertical turbine to be placed in commercial service, a 500 KW
machine, was shipped in February 1903 to the Newport and Fall River
Company of Newport, Rhode Island. The first large Curtis turbine, and
the machine which demonstrated the working feasibility of the design,
was the 5,000 KW turbogenerator installed in the Fisk Street Generating
Station of the Commonwealth Electric Company of Chicago in 1903. This
turbine, removed to the Turbo-Generator Development Laboratory of
General Electric's Schenectady plant, was designated a National
Historic Mechanical Engineering Landmark by the American Society of
Mechanical Engineers in 1975. The Fisk Street Station was the first '
power house designed specifically for vertical turbogenerators; room
was allowed, though, should the unit have to be replaced by the more
traditional reciprocating engine. (A.S.M.E. 1975, p. 4)
The Curtis turbogenerator was quickly successful. In the first fifteen
months of sales, ending in 1903, General Electric sold 225,000 H.P. of
Curtis turbines*. (Westinghouse, by comparison, had sold some 300,000
H.P. of Parsons turbines for land use, and 33,000 H.P. for marine use,
in the previous twelve years.) By June 1905, there were 224 units of
the "larger sizes" in operation, totaling 350,000 H.P., including ten
5,000 KW machines. (Robinson 1937, pp. 241-242; G.E. Pamphlet 1907, p.
5) By September of 1906, Charles B. Burleigh reported to the National
Association of Cotton Manufacturers "more than twice as many Curtis
turbines in commercial operation in this country as there are of any
other manufacture and more than the number of horse power of vertical
shaft turbines in this country than there are of horizontal shaft
turbines of all other manufacture ..." {Burleigh 1906, p. 40) In
three years of manufacture, the Curtis machirfe demonstrated its
capacity as a cheap, compact, powerful, and efficient prime mover for
electrical generation.3 The design won the only grand prize for steam
turbines at the St. Louis Exposition of 1904 and a gold medal at the
Lewis and Clark Exposition in Oregon in 1905. (Burleigh 1906, p. 28)
Reasons for the superiority of the Curtis vertical steam turbine were
often cited in long lists published by General Electric. Most often,
these and other commentators focused on four major points: efficiency
at all Toads, simplicity, low maintenance, and economy in space. (G.E.
Pamphlet 1907, p. 5) To this should be added the dramatic improvements
achieved by General Electric during the decade of the 1900s. The
Curtis units were significantly more efficient because they used both
velocity and pressure compounding, because they did not require
converting reciprocating motion to rotary motion, and because of a
unique method of governing or maintaining speed under varying loads.4.
The most important reason for its efficiency, explained an article in
the General Electric Review, was the combination of pressure and
velocity compounding to deal with the difference between the velocity
of the steam some 3,600 feet per second, and the desired speed of the
turbine, much slower than that. Two pressure stages, each of three
wheels, give.a peripheral velocity of 425 feet per second in the Curtis
turbine. To use steam at an equal efficiency in other turbines would
require, according to the article, eighteen steps of
pressure-compounded Oe Laval wheels, or 72 expansion stages (36 fixed
and 36 movable) in a Parsons turbine. (Burleigh 1910, p. 510)
The simplicity of the Curtis units derived from several features. They
mounted both prime mover and generator on a single shaft and required
far fewer moving parts. . Because there were none of the lateral strains
and thrusts of the reciprocating engines, foundations were "a matter of
less importance than with any other steam prime mover." (Burleigh 1906,
p. 51) Maintenance was easier because the vertical configuration left
all parts of the- turbine and generator accessible and because the
single turbogenerator shaft rested on a single thrust bearing that was
easily replaced. (Burleigh 1906, p. 40) In May 1904, General Electric
published a pamphlet including four pages of scale drawings comparing
the floor space and height required by engines and Curtis turbines in
100 KW, 500 KW, 1,500 KW and 5,000 KW sizes clearly demonstrating the
space savings of the turbines, (pp. 25-28) Given the pressures on
central-city generating facilities, it seemed clear the vertical
"compact design results in marked savings in land, buildings,
foundations, and equipment." (Burleigh 1906, p. 70)
Finally, General Electric achieved significant improvement in the
design of the units. As one example of the results of this effort, the
four original 5,000 KW units installed in the Fisk Street Station in
Cfci^go.m 1904^,-were replaosd by 12,000 KW units in 1909. "These
occupy no greater space than the original machines and-nt> -Irorawe in
the capacity of the boilers supplying them was necessary." The report
went on to claim the "kilowatt per square feet of station has been more
than doubled" while also achieving a 25 percent increase in steam
economy. (Parker 1910, p. 64-65) The message to those needing to
exoand electrical generating capacity but unable to expand existing
stations was clear. By 1909, 1,200 Curtis units were Installed across
the United States and another 200 were on order. (Kirk!and 1909, p.
101)
The vertical arrangement of the Curtis- turbine was successful for the
early middle-sized, slowly rotating machines. Between 1908 and 1913,
however, General Electric gradually abandoned this form. Customers
demanded larger machines, which meant more stages and a longer shaft;
this was more easily accomodated in a horizontal configuration. New
materials made possible faster speeds, up to 3,600 rpm, which required
a stiffer structure than could be'provided to a vertical machine.
(A.S.M.E. 1975, p. 6) These new materials also proved the demise of
the Curtis velocity-compounded multiple-row wheels. An engineer,
reviewing the history of the Curtis turbine, wrote:
. . . the reasons why the multi-row Curtis wheel was so successful
are not . . . self-evident.
The facts of the case seem to be that the time was not yet ripe
for an expensive multi-stage single-row construction such as
characterizes a modern high-efficiency machine. The Curtis
multi-row wheels proved far mor efficient than the single-stage De
Laval machine and far cheaper, more compact, and rugged than the
many-stage reaction Parsons machines of that day. The Oe Laval
machine was decidedly limited in capacity. With only low-grade
materials available, the Curtis arrangement was ideally adapted to
effect the required energy conversion with a minimum of wheel
speed; whereas, neither a single-wheel design nor a reaction
design could do this. Some such considerations surely explain the
general preference for the Curtis turbine at the time and its
great-success. (Robinson 1937, p. 242)
For this brief period, 1903-1913 (the Georgetown units were installed
in 1906 and 1907), the vertical steam turbine generator units
manufactured by General Electric swept the market. General Electric
established its significance as a manufacturer of steam turbines, and
in fact, rapidly developed the technology they pioneered with the
Curtis machine. Requiring one-tenth the space of a corresponding
engine-generator unit and one-third to one-half the steam, the General
Electric units made possible the large central-station generating
plants that characterized urban electrification for at least a quarter
of a century. Yet the success of these units was short-lived: General
Electric itself saw the limits on the vertical configuration and began
as early as 1908 to move toward a horizontal Curtis unit for units of
the largest size (20,GOO KW was apparently the upper range for the
vertical units). The tremenotms 'expansion iivdemBnd for ;etectric4ty
forced the rapid replacement of smaller and less efficient units
leaving only two solitary surviving examples of what was once a
development of overwhelming significance. Even at Georgetown, a third
horizontal unit, installed in a small addition to the original plant in
1919, is remarkably smaller than either of the first two vertical units
and yet produces power roughly equal the two older units combined, thus
repeating the very-process that once established the hegemony of the
General Electricity/Curtis vertical steam turbine generator over the
engine/generator units in use in 1900.
In 1882, Thomas Edison opened his Pearl Street Plant in New York City
to initiate the Electrical Age in urban America. While advocates
debated the relative merits of direct and alternating current,
eventually settling on the latter, reciprocating steam engines driving
a separate electrical generator appeared from coast to coast. As
demand for electricity increased, companies tried to increase both the
size and number of generating units, but were beginning to encounter
limits on engine/generator size as well as station size. In an early
attempt to alleviate this threat, the Westinghouse Company secured the
patents to the Parsons steam turbine (patented 1884), the first
successful industrial turbine, much smaller than equal engine/generator
units, even if no more efficient. For nearly a decade, Westinghouse
clearly had the upper hand. The growth of central generating stations
required increases in capacity and the massive engine/generator units
with their vibration limits and size requirements could not meet that
demand. Westinghouse had the only operating turbine on the market.
Charles G. Curtis (1860-1953) received patents 566,967, 566,968, and -
566,969, protecting the basic principles of the Curtis turbine, in
September, 1896. These patents cover, respectively, the expansion
nozzles and their regulation, the concept of velocity compounding, .and
the concept of pressure compounding. Curtis assigned all three patents
to his own company, the Curtis Company, which one year later entered
into a liscensing agreement with the General Electric Company. For
$1,500,000, General Electric received rights to all uses of the Curtis
turbine except aerial and marine propulsion.3.
General Electric formed a hew division to undertake the development and
manufacture of the Curtis turbine. From 1897 to 1902, General Electric
built and tested a variety of designs based on the Curtis patents.
Until 1900, Charles Curtis himself directed this research.2 in 1901,
William Le Roy Errenet took charge of the development of the Curtis
turbine. Eamet (1858-1941), a central figure in General Electric's
development of prime movers, trained at the U.S. Naval Academy and
•worked at various .^obs m the ^lactrteal industry before he joined the
new General Electric in 1892. General Electric, concerned by the lack
of progress with the Curtis turbine project offered Emmet charge of the
turbine project at a point when it was considering dropping it. Emmet
realized the difficulties but thought the work extremely important and
urged that it be allowed to proceed. In his autobiography he noted his
overall impression of the work: "I think it is safe to say that there
have not been many jobs more extensive and strenuous in the art of
engineering." (Emmet 1931, p. 142)
Emmet directed the Curtis turbine project for twelve years, until 1913.
Many of the features of the machine were incorporated as a result of
his guidance, including the vertical orientation of the larger sizes.
Emmet invented the oil-supported step bearing used to test the
generators installed at Niagara Falls and made use of them in the
Curtis turbine. He was also responsible for the selection of the sizes
of the turbine., and for meeting'the deadline'for the delivery of the
first machines. (Enmet 1931, p. 147)
Between 1897 and 1902, General Electric made a number of small turbines
based on Curtis's principles. These were used for tests. The first
placed in operation was a 500 KW unit installed at the General Electric
plant in Schenectady in November, 1901. (Robinson 1937, pp. 239-240)
The first vertical turbine to be placed in commercial service, a 500 KW
machine, was shipped in February 1903 to the Newport and Fall River
Company of Newport, Rhode Island. The first large Curtis turbine, and
the machine which demonstrated the working feasibility of the design,
was the 5,000 KW turbogenerator installed in the Fisk Street Generating
Station of the Commonwealth Electric Company of Chicago in 1903. This
turbine, removed to the Turbo-Generator Development Laboratory of
General Electric's Schenectady plant, was designated a National
Historic Mechanical Engineering Landmark by the American Society of
Mechanical Engineers in 1975. The Fisk Street Station was the first '
power house designed specifically for vertical turbogenerators; room
was allowed, though, should the unit have to be replaced by the more
traditional reciprocating engine. (A.S.M.E. 1975, p. 4)
The Curtis turbogenerator was quickly successful. In the first fifteen
months of sales, ending in 1903, General Electric sold 225,000 H.P. of
Curtis turbines*. (Westinghouse, by comparison, had sold some 300,000
H.P. of Parsons turbines for land use, and 33,000 H.P. for marine use,
in the previous twelve years.) By June 1905, there were 224 units of
the "larger sizes" in operation, totaling 350,000 H.P., including ten
5,000 KW machines. (Robinson 1937, pp. 241-242; G.E. Pamphlet 1907, p.
5) By September of 1906, Charles B. Burleigh reported to the National
Association of Cotton Manufacturers "more than twice as many Curtis
turbines in commercial operation in this country as there are of any
other manufacture and more than the number of horse power of vertical
shaft turbines in this country than there are of horizontal shaft
turbines of all other manufacture ..." {Burleigh 1906, p. 40) In
three years of manufacture, the Curtis machirfe demonstrated its
capacity as a cheap, compact, powerful, and efficient prime mover for
electrical generation.3 The design won the only grand prize for steam
turbines at the St. Louis Exposition of 1904 and a gold medal at the
Lewis and Clark Exposition in Oregon in 1905. (Burleigh 1906, p. 28)
Reasons for the superiority of the Curtis vertical steam turbine were
often cited in long lists published by General Electric. Most often,
these and other commentators focused on four major points: efficiency
at all Toads, simplicity, low maintenance, and economy in space. (G.E.
Pamphlet 1907, p. 5) To this should be added the dramatic improvements
achieved by General Electric during the decade of the 1900s. The
Curtis units were significantly more efficient because they used both
velocity and pressure compounding, because they did not require
converting reciprocating motion to rotary motion, and because of a
unique method of governing or maintaining speed under varying loads.4.
The most important reason for its efficiency, explained an article in
the General Electric Review, was the combination of pressure and
velocity compounding to deal with the difference between the velocity
of the steam some 3,600 feet per second, and the desired speed of the
turbine, much slower than that. Two pressure stages, each of three
wheels, give.a peripheral velocity of 425 feet per second in the Curtis
turbine. To use steam at an equal efficiency in other turbines would
require, according to the article, eighteen steps of
pressure-compounded Oe Laval wheels, or 72 expansion stages (36 fixed
and 36 movable) in a Parsons turbine. (Burleigh 1910, p. 510)
The simplicity of the Curtis units derived from several features. They
mounted both prime mover and generator on a single shaft and required
far fewer moving parts. . Because there were none of the lateral strains
and thrusts of the reciprocating engines, foundations were "a matter of
less importance than with any other steam prime mover." (Burleigh 1906,
p. 51) Maintenance was easier because the vertical configuration left
all parts of the- turbine and generator accessible and because the
single turbogenerator shaft rested on a single thrust bearing that was
easily replaced. (Burleigh 1906, p. 40) In May 1904, General Electric
published a pamphlet including four pages of scale drawings comparing
the floor space and height required by engines and Curtis turbines in
100 KW, 500 KW, 1,500 KW and 5,000 KW sizes clearly demonstrating the
space savings of the turbines, (pp. 25-28) Given the pressures on
central-city generating facilities, it seemed clear the vertical
"compact design results in marked savings in land, buildings,
foundations, and equipment." (Burleigh 1906, p. 70)
Finally, General Electric achieved significant improvement in the
design of the units. As one example of the results of this effort, the
four original 5,000 KW units installed in the Fisk Street Station in
Cfci^go.m 1904^,-were replaosd by 12,000 KW units in 1909. "These
occupy no greater space than the original machines and-nt> -Irorawe in
the capacity of the boilers supplying them was necessary." The report
went on to claim the "kilowatt per square feet of station has been more
than doubled" while also achieving a 25 percent increase in steam
economy. (Parker 1910, p. 64-65) The message to those needing to
exoand electrical generating capacity but unable to expand existing
stations was clear. By 1909, 1,200 Curtis units were Installed across
the United States and another 200 were on order. (Kirk!and 1909, p.
101)
The vertical arrangement of the Curtis- turbine was successful for the
early middle-sized, slowly rotating machines. Between 1908 and 1913,
however, General Electric gradually abandoned this form. Customers
demanded larger machines, which meant more stages and a longer shaft;
this was more easily accomodated in a horizontal configuration. New
materials made possible faster speeds, up to 3,600 rpm, which required
a stiffer structure than could be'provided to a vertical machine.
(A.S.M.E. 1975, p. 6) These new materials also proved the demise of
the Curtis velocity-compounded multiple-row wheels. An engineer,
reviewing the history of the Curtis turbine, wrote:
. . . the reasons why the multi-row Curtis wheel was so successful
are not . . . self-evident.
The facts of the case seem to be that the time was not yet ripe
for an expensive multi-stage single-row construction such as
characterizes a modern high-efficiency machine. The Curtis
multi-row wheels proved far mor efficient than the single-stage De
Laval machine and far cheaper, more compact, and rugged than the
many-stage reaction Parsons machines of that day. The Oe Laval
machine was decidedly limited in capacity. With only low-grade
materials available, the Curtis arrangement was ideally adapted to
effect the required energy conversion with a minimum of wheel
speed; whereas, neither a single-wheel design nor a reaction
design could do this. Some such considerations surely explain the
general preference for the Curtis turbine at the time and its
great-success. (Robinson 1937, p. 242)
For this brief period, 1903-1913 (the Georgetown units were installed
in 1906 and 1907), the vertical steam turbine generator units
manufactured by General Electric swept the market. General Electric
established its significance as a manufacturer of steam turbines, and
in fact, rapidly developed the technology they pioneered with the
Curtis machine. Requiring one-tenth the space of a corresponding
engine-generator unit and one-third to one-half the steam, the General
Electric units made possible the large central-station generating
plants that characterized urban electrification for at least a quarter
of a century. Yet the success of these units was short-lived: General
Electric itself saw the limits on the vertical configuration and began
as early as 1908 to move toward a horizontal Curtis unit for units of
the largest size (20,GOO KW was apparently the upper range for the
vertical units). The tremenotms 'expansion iivdemBnd for ;etectric4ty
forced the rapid replacement of smaller and less efficient units
leaving only two solitary surviving examples of what was once a
development of overwhelming significance. Even at Georgetown, a third
horizontal unit, installed in a small addition to the original plant in
1919, is remarkably smaller than either of the first two vertical units
and yet produces power roughly equal the two older units combined, thus
repeating the very-process that once established the hegemony of the
General Electricity/Curtis vertical steam turbine generator over the
engine/generator units in use in 1900.
[HAER-data, p75-9
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