convert

There’s an invention that’s been working for

75 years along the Susquehanna River in
Lancaster County, Pa., with negligible wear,
while withstanding a force of more than
220 tons.

The Susquehanna Section of the American

Society of Mechanical Engineers dedicated
that invention — a 48-inch-diameter thrust
bearing — on Saturday, June 27, 1987, as
its 23rd International Historic Mechanical
Engineering Landmark.

The bearing is the brainchild of the late

professor Albert Kingsbury, an engineering
genius who personally supervised its installa-
tion in the 10,000-horsepower Unit 5 of the
10-unit Holtwood Hydroelectric Station, June 22
through 27, 1912. Holtwood today is owned
and operated by Pennsylvania Power & Light
Co. It was built and operated until 1955 by
Pennsylvania Water & Power Co.

All bearings in rotating machinery need to

overcome the effects of friction between re-
volving parts and stationary parts. A thrust
bearing specifically overcomes the friction
created when a shaft exerts a force in a
direction parallel to its axis of rotation.

Helicopter rotors and airplane or boat pro-

pellers, for instance, need thrust bearings on
their shafts. So do hydroelectric turbine-
generator units.

Until Kingsbury came onto the scene, units

like Holtwood’s represented the upper size
limit of hydroelectric design. The rotating
elements at Holtwood Unit 5 have a com-
bined weight of more than 180 tons, and
the downward force of water passing
through the turbine adds another 45 tons.

Roller thrust bearings once used in such

installations rarely lasted more than two
months before needing repair or replacement.

Then Kingsbury came along with the de-

ceptively simple idea that instead of roller or
ball bearings, a thin film of oil could support
the massive weight — and practically elimi-
nate mechanical wear in the bargain.

The principle of the discovery — in Kings-

bury’s own words — was this:

In  reading  (a)  paper  dealing  with  flat
surfaces,  it  occurred  to  me  that  here
was  a  possible  solution  to  the  trou-
blesome  problem  of  thrust  bearings
...if  an  extensive  flat  surface  rubbed
over  a  flat  surface  slightly  inclined
thereto,  oil  being  present,  there
would  be  a  pressure  distributed
about  as  sketched...

Former Holtwood superintendent W. Roger Small Jr.
checks the glass inspection port on the Unit 5
thrust deck that enables operators to view the

oil-bathed bearing during operation.

The  maximum  pressure  would  occur
somewhat  beyond  the  center  of  the
bearing  block  in  the  direction  of  mo-
tion  and  the  resultant  would  be  be-
tween  that  maximum  and  the  center
line  of  the  block.  It  occurred  to  me
that  if  the  block  were  supported
from  below  on  a  pivot,  at  about  the
theoretical  center  of  pressure,  the  oil
pressures  would  automatically  take
the  theoretical  form,  with  a  resulting
small  bearing  friction  and  absence  of
wear  of  the  metal  parts,  and  that  in
this  way  a  thrust  bearing  could  be
made,  with  several  such  blocks  set
around  in  a  circle  and  with  proper
arrangements  for  lubrication.

The diagram at left is taken from a sketch by Kings-

bury himself, showing his insight into the pressure
distribution in an offset bearing shoe. Below, a model
of the Kingsbury thrust bearing is affixed to Holtwood’s
Unit 5 generator, so that visitors can see the inge-

nious way its parts interact.

On the 25th anniversary of its installation,
Kingsbury (right) returned to Holtwood for

a look at the Unit 5 thrust bearing. With
him is Frederick A. Allner, who eventually
became a Pennsylvania Water & Power Co
vice president. The arc-shaped piece in

front of Allner is one of the bearing shoes

that had been removed for the occasion.

Kingsbury’s design could support 100

times the load of the previously used roller
bearings.

The top half of his bearing design is a flat,

cast-iron ring, called a “runner.” The runner
rests on six flat shoes, shaped like wedges
of pie to match the shape of the ring.

The entire bearing is bathed in 570 gal-

lons of oil. Each of the shoes is pivot-
mounted so that it can rock a bit. How this
happens is shown in the diagram, copied
from Kingsbury’s original sketch in which he
showed the pressure distribution in the offset
shoes.

The rotating motion of the cast-iron runner

squeezes oil between it and the shoes, and
the oil actually supports the weight, with no
physical contact between the runner and the
shoes.

As a kind of engineering “bonus,” the

design is such that the faster a unit runs,
the more weight the bearing is capable of
carrying.

Kingsbury returned to Holtwood once —

to mark the 25th anniversary of the installa-
tion of bearing No. 1 in the plant’s Unit 5.
Amid all the pomp and ceremony of the oc-
casion, he took time out to smear his initials
in the oil film of a Kingsbury bearing shoe
that the owners had on display.

Incidentally, the contract between PW&P

and Kingsbury, which agreement the profes-
sor described as “a stiff one,” was for $2,650
for the construction and installation of that
first bearing.

At Holtwood today, a model of the bear-

ing is attached to Unit 5, along with a plaque
reading:

“The first Kingsbury thrust bearing ever

installed on a hydro-electric generation
unit was put into service in this machine
on June 22, 1912. It carries a weight of
220 tons.

“When the generator was rebuilt for

60-cycle service in 1950, the original
Kingsbury bearing was retained, as it was
in perfect condition.

“Not a single part has ever been

replaced.”

The Kingsbury company

Albert Kingsbury was born in Morris, Ill.,

in 1863, the son of a Quaker mother and
Presbyterian father. His lineage went back to
English immigrants who landed in Massa-
chusetts in the 17th century.

A well-rounded individual with a sense of

humor, Kingsbury was equally at ease work-
ing with machinery, singing, playing the
flute or reading in Spanish, Italian, Greek,
French, German or Danish.

Throughout his early life, there remained a

thread of interest in coefficients of friction
that appeared to have begun when he under-
took the testing of bearing metals while
studying mechanical engineering at Cornell
University.

Kingsbury took over the testing of half-

journal bearings at Cornell in research under-
written by the Pennsylvania Railroad Co.
After carefully scraping and refitting all the
test bearings there, he discovered that they
exhibited identical characteristics and showed
no detectable wear.

He was to remain intrigued by the mys-

teries of friction and the properties of lubri-
cants for the rest of his life, whether teaching
at New Hampshire College (Durham) after his
graduation, working in private industry or
teaching again at Worcester Polytechnic
Institute.

The inspiration for Kingsbury’s tilting-pad

bearing came when he read an 1886 paper
by Osborne Reynolds on properties of fluid-
film-lubricated bearings. Kingsbury built a
successful thrust bearing in 1898, while at
New Hampshire College.

Eventually lured away from the academic

life by his desire to work more closely with
lubrication problems, Kingsbury nonetheless
was awarded two honorary doctorates in
recognition of his contributions to the
knowledge of tribology — the study of fric-
tion and ways to overcome its effects.

He applied for a U.S. patent in 1907, and

eventually was awarded Patent No. 947,242
in 1910.

It was when Kingsbury was working at

the East Pittsburgh works of the Westing-
house Electric and Manufacturing Co. that
this daringly innovative engineer chanced
upon a daringly innovative company —
Pennsylvania Water & Power Co. — that was
in need of a bearing of the sort Kingsbury
wanted to demonstrate on a commercial
scale.

PW&P was a struggling company between

1910 — when Holtwood went into operation
— and 1914, when the utility was able to
turn around its financial fortunes.

Kingsbury, for his part, took the money

from a matured insurance policy and used it
to pay Westinghouse for building the first
thrust bearing that was installed at Holtwood.

Both he and PW&P were betting their fu-

tures on the success of his bearing in replac-
ing the roller bearings that used to wear out
in a matter of months at Holtwood and sim-
ilar hydroelectric installations.

The first time it was installed, it looked

like an overheated failure. But Kingsbury
took it back to East Pittsburgh and applied
that same careful scraping technique whose
results puzzled him at Cornell. Within five
days, the bearing was installed and running
without problems.

After three months, the bearing was taken

apart and found to be in perfect condition.
PW&P bought more, and eventually put them
on all 10 Holtwood hydroelectric units. Cal-
culations after that first inspection showed
that the bearing should last 330 years be-
fore the shoes’ bearing surface would be
half worn away.

After four years and another inspection,

recalculation indicated a more than
1,320-year life span.

When the unit was again inspected in

1969, the bearing was stall in nearly new
condition.

Kingsbury’s bearing made possible the

design of much larger hydroelectric units,
such as those of the Tennessee Valley Au-
thority and Bonneville Power Authority and
at the Hoover and Grand Coulee dams.

In addition, Kingsbury bearings have been

used extensively in marine propulsion — for
the propeller shafts of large ships and even
nuclear-powered submarines. The first such
application was on U.S. Navy ships in 1917.

History of Holtwood Hydro

The Holtwood Hydroelectric Station was

built between 1905 and 1910 by the Penn-
sylvania Water & Power Co. PW&P merged
with Pennsylvania Power & Light Co., the
plant’s present owner and operator, in 1955.

The Kingsbury thrust bearing is far from

the only technology pioneered at Holtwood.

A hydraulic laboratory existed there for

many years, and in it were tested not only
the runner (turbine blade) design for the Safe
Harbor Hydroelectric Development, eight
miles upriver from Holtwood, but also run-
ners for many large hydroelectric develop-
ments throughout the country, including
Bonneville and Santee-Cooper.

Another interesting facet of “river technol-

ogy” was the dredging and burning of an-

thracite culm, or “fines” (waste coal that

washed into the river from the anthracite
belt as far north as Luzerne and Lackawan-
na counties).

For years, commercial dredging was done

in the Holtwood impoundment (Lake Aldred),
and later in the Safe Harbor impoundment
(Lake Clarke). Indeed, Holtwood Steam Elec-
tric Station was built to burn river coal, and
did so until cleaner coal-mining and process-
ing methods shut off the flow of available
“fines” and environmental regulations in 1972
made it impractical to continue dredging.

Other technological pioneering at Holt-

wood included PW&P’s testing of lightning-
protection systems and water-deluge fire-

fighting systems to protect large transform-
ers. The systems protecting transformers at
all PP&L plants today are direct descendants
of the prototypes developed at Holtwood.

Notwithstanding the embryonic state of

large-project engineering and construction
techniques when Holtwood was built, its
massive concrete dam has withstood all ma-
jor floods on the Susquehanna, including the
devastating flood of 1936, the assault of
Tropical Storm Agnes in 1972 and a massive
ice jam in 1978.

Thanks to PP&L’s ongoing “Extended Life”

program for its generating stations, Holt-
wood is expected to have a useful life well
into the next century, and far longer than
might have been projected for it in 1910.

At the time of the Kingsbury thrust bear-

ing’s dedication as an International Historic
Mechanical Engineering Landmark, a com-
plete rebuild of Holtwood’s hydroelectric
Unit 8 was in progress. Other units will be
rebuilt on a continuing schedule.

With that kind of maintenance and with

original equipment of the quality of the
Kingsbury bearing, it’s possible that Holt-
wood Hydroelectric Station may never “wear
out.”

Seen here from the York County side of
the river, Holtwood Hydroelectric Station

has been a familiar landmark along the

Susquehanna for more than 76 years.

Text of the Kingsbury
Plaque at Holtwood

(Editor’s note: The ASME
plans to erect a plaque for

the Michell bearing at another
location. That plaque will re-
peat the last paragraph from
the Kingsbury plaque, but
with Kingsbury’s name substi-

tuted for Michell’s.)

The ASME’s History and Heritage
Program

The ASME History and Heritage program

began in September 1971. To implement
and achieve its goals, ASME formed a His-
tory and Heritage Committee, composed of
mechanical engineers, historians of technol-
ogy, and the curator of Mechanical and Civil
Engineering at the Smithsonian Institution.
The committee provides a public service by
examining, noting, recording and acknowl-
edging mechanical engineering achievements
of particular significance. For further informa-
tion, please contact the Public Information
Department, American Society of Mechanical
Engineers, 354 East 47th Street, New York,
N.Y. 10017, (212) 705-7740.

About the Landmarks

The Kingsbury Bearing is the 23rd Interna-

tional Historic Mechanical Engineering Land-
mark to be designated. Additionally, since
the ASME National Historic Mechanical Engi-
neering Program began in 1971, 87 National
Historic Mechanical Engineering Landmarks,
one International Mechanical Engineering
Heritage Site, one International Mechanical
Engineering Heritage Collection, and two Na-
tional Mechanical Engineering Heritage Sites
have been recognized. Each reflects its influ-
ence on society in its immediate locale, na-
tionwide or throughout the world.

According to David P. Kitlan, the ASME

Susquehanna Section’s History & Heritage
Committee chairman, this region of Pennsyl-
vania is particularly rich in examples of
engineering innovation and progress, and
the section has sponsored more National
Historic Mechanical Engineering Landmarks
than any other in the country.

The Kingsbury bearing, however, is the

section’s first International ASME Historic
Mechanical Engineering Landmark, so desig-
nated because of the global consequences of
Kingsbury’s invention and its applications.

Other engineering accomplishments al-

ready recognized as “landmarks” in Pennsyl-
vania include: The Pennsylvania Railroad
“GG-1” electric locomotive No. 4800 at
Strasburg; the Worthington cross-compound
steam pumping engine at York; the Kaplan
hydroelectric turbine at York Haven Hydro-
electric Plant, York Haven; the Cornwall Iron
Furnace in Lebanon County; the Fairmount
Water Works in Philadelphia; the steam
engines of the USS Olympia, berthed in Phil-
adelphia; the Monongahela and Duquesne
inclines at Pittsburgh: and the Drake oil well
at Titusville.

An ASME landmark represents a progres-

sive step in the evolution of mechanical
engineering. Site designations note an event
or development of clear historical impor-
tance to mechanical engineers. Collections
mark the contributions of a number of ob-
jects with special significance to the histor-
ical development of mechanical engineering.

The ASME Historical Mechanical Engineer-

ing Program illuminates our technological
heritage and serves to encourage the preser-
vation of the physical remains of historically
important works. It provides an annotated
roster for engineers, students, educators,
historians and travelers. It helps establish
persistent reminders of where we have been
and where we are going along the divergent
paths of discovery.

INTERNATIONAL HISTORIC MECHANICAL ENGINEERING LANDMARK

KINGSBURY THRUST BEARING

HOLTWOOD UNIT #5

HOLTWOOD, PA.

1912

THE LOAD IN A KINGSBURY BEARING IS CARRIED BY A WEDGE-SHAPED OIL FILM FORMED BETWEEN

THE SHAFT THRUST-COLLAR AND A SERIES OF STATIONARY PIVOTED PADS OR SEGMENTS. THIS RE-

SULTS IN AN EXTREMELY LOW COEFFICIENT OF FRICTION AND NEGLIGIBLE BEARING WEAR.

ALBERT KINGSBURY (1863-1944) DEVELOPED THE PRINCIPLE IN THE COURSE OF BEARING AND

LUBRICATION INVESTIGATIONS COMMENCING IN 1888 WHILE A STUDENT. HIS FIRST EXPERIMENTAL
BEARING WAS TESTED IN 1904, AND HE FILED FOR A PATENT IN 1907 — GRANTED IN 1910.

THE FIRST KINGSBURY BEARING IN HYDROELECTRIC SERVICE — ONE OF ITS MAJOR APPLICATIONS —

WAS INSTALLED HERE IN 1912. IT REMAINS IN FULL USE TODAY. KINGSBURY THRUST AND JOURNAL
BEARINGS HAVE BEEN APPLIED TO LARGE MACHINERY OF ALL TYPES THROUGHOUT THE WORLD.

IN ONE OF THOSE COINCIDENCES WITH WHICH THE HISTORY OF TECHNOLOGY IS STREWN, AUSTRA-

LIAN A. G. M. MICHELL SIMULTANEOUSLY AND INDEPENDENTLY INVENTED A BEARING ON THE SAME
PRINCIPLE, THE TYPE BEING KNOWN IN MANY PARTS OF THE WORLD BY HIS NAME.

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS — 1987

History and description of PP&L

Pennsylvania Power & Light Co., incor-

porated June 4, 1920, now serves

2.5 million people in all or parts of 29
Central Eastern Pennsylvania counties.

Thomas A. Edison himself established

several of the companies that were pre-
cursors of PP&L, and he built the world’s
first three-wire electric supply system in
Sunbury. The first electrically lighted
hotel and church both were located
within what is now PP&L’s service area.

Ideally located near a majority of the

mid-Atlantic states’ population, PP&L
contributes to the economic health and
growth of the area not only by provid-
ing dependable and economical electrici-
ty, but by an aggressive economic de-
velopment program to nurture existing
companies and encourage others to
locate in its territory.

Holtwood Hydroelectric Station, whose

first unit was completed in 1910, before
PP&L was formed, is the oldest of PP&L’s
generating facilities. The Holtwood dam
was, for a short time, the longest in the
nation, and the generating plant was
the largest hydro station as well.

Also on the site is the Holtwood

Steam Electric Station, location of the
nation’s largest anthracite-burning boiler.

Other PP&L hydro facilities are the

wholly owned Wallenpaupack Hydro-
electric Station, completed in 1926, and
the Safe Harbor Hydroelectric Develop-
ment (one-third interest), which dates
back to 1931.

The Sunbury Steam Electric Station,

which went on-line in 1949, is PP&L’s
other anthracite-burning facility. Its four
anthracite-fired boilers make it the
largest anthracite-burning generating
plant in the nation.

The company has four plants where

bituminous coal is burned: Sunbury;
Martins Creek Steam Electric Station —
on line in 1954; Brunner Island Steam
Electric Station — 1961; and Montour
Steam Electric Station — 1972.

The Martins Creek station also is the

location of two heavy-oil-burning units,
dating to 1975.

PP&L’s newest large plant is the

nuclear-powered Susquehanna Steam
Electric Station, with an in-service date
of 1983.

In addition, PP&L owns part interests

in the Keystone and Conemaugh plants
in western Pennsylvania.

More than 25 light-oil-fueled combus-

tion turbines are located throughout the
PP&L system to provide additional peak-
load power when needed.

The ASME

All PP&L’s plants combined have a ca-

pacity of more than 8.8 million kilowatts.

Formed in 1880, the American Society

of Mechanical Engineers is a profes-
sional society dedicated to the mainte-
nance of high engineering standards
and to education of the public in mat-
ters relating to engineering.

Acknowledgments

The American Society of Mechanical Engineers

Richard Rosenberg, President
Richard A. Hirsch, Vice President, Region III
Michael R. C. Grandia, History and Heritage Chairman, Region III
Dr. David L. Belden, Executive Director

The ASME Susquehanna Section

Theodore Taormina, Chairman
William J. Stewart, Secretary-Treasurer
David P. Kitlan, Chairman, History and Heritage Committee

The ASME National History and Heritage Committee

Dr. R. C. Dalzell, Chairman
Robert M. Vogel, Secretary
Dr. Robert B. Gaither

Dr. R. S. Hartenberg

Dr. J. Paul Hartman
Dr. Euan F. C. Somerscales
J. P. Van Overveen
Carron Garvin-Donohue, Staff liaison

Pennsylvania Power & Light Co.

Robert K. Campbell, President and Chief Executive Officer
John T. Kauffman, Executive Vice President-Operations
Thomas M. Crimmins Jr., Vice President-Power Production
Alden F. Wagner Jr., Superintendent of Plant-Holtwood Operations
N. Christian Porse, Supervisor-Hydro Generating Plant
James K. Witman, Power Production Engineer

Kingsbury, Inc.

Margaretta Clulow, Chairman
George Olsen, President
Richard S. Gregory, Vice President and General Manager
Andrew M. Mikula, Director of Marketing

References for Further Reading:

Mechanical Engineering magazine, December 1950, p. 957
PP&L Insights newsletter, June 24, 1983, p. 2
PP&L REPORTER magazine, October 1985, p. 10

The American Society of

Mechanical Engineers

345 East 47th Street, New York, NY 10017

Specifications for the first Kingsbury bearing at Holtwood:

Designed for a 12,000-kilowatt water-wheel-driven generator

Capable of supporting a 400,000-lb. load in continuous operation

To operate between 94 and 116 RPM

Lubrication to be a high grade oil known as “Renown Engine Oil”

Intake temperature of oil to be not more than 40 degrees C

Must be capable of 10 RPM for 15 minutes and also 20 RPM for one hour
without undue heating of any part, providing oil is supplied at 17.5 gallons
per minute

Must be capable of operating at a runaway speed of 170 RPM for one hour,
providing oil is supplied at 17.5 gallons per minute

Must be capable of operating during one-half hour of interruption of oil cir-
culation, providing no oil is lost from the casing – or for 20 minutes at an
overspeed not to exceed 40 percent above 116 RPM

Diameter: 48 inches

Height: 24 inches

Approximate weight: 2.5 tons

The ASME was assisted in preparation of this publication by Pennsylvania Power & Light Co. and Kingsbury. Inc

ASME Identification Number HH 0587

(6M 6/87)

H123