American Society of Civil Engineers.

Transactions of the American Society of Civil Engineers (Volume 81) online

. (page 141 of 167)
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1.9378


82


51.6601


2.0144


58.8957


2.0935


65.1577


2.1083


70.4949


2.0734


83


49.6457


2.0950


56.8022


2.1983


63.0494


2.2348


1 68.4215


2.2186


84


47.5507


2.1788


54.6040


2.3081


60.8146


3.3689


66.2029


2.3739


85


45.3719


2.2659


52.2959


2.4235


58.4457


2.5110


63.8290


2.5400


86


43.1060


2.3566


49.8724


2.5447


.55.9347


2.6616


60.2890


2.7179


87


40.7494


2.4508


47.3277


2.6719


53.2731


2.8213


58.5711


2.9081


88


38.2986


. 2.5489


44.6558


2.8055


50.4518


2.9906


55.6630


3.1117


80


35.7497


2.6508


41.8503


2.9458


47.4612


3.1701


52.5513


3.3395


90


33.0989


2.7568


38.9045


3.0931


44.2911


3.3603


; 49.2218


3.5635


91


30.3421


2.8671


35.8114


3.2477


40.9308


3.5619


45.6593


3.8119


92


27.4750


2.9818


33.5637


3.4101


37.3689


3.7756


41.8474


4.0788


93


24.4932


3.1011


29.1536


3.5806


j 33.5933


4.0021


87.7686


4.3643


94


21.3921


3.2251


35.5730


3.7597


29.5912


4.2423


33.4043


4.6698


95


18.1670


3.3541


21.8133


3.9477


25.. 3489


4.4968


28.7345

1


4.9967


96


14.8129


3.4883


17.8656


4.1450


20.8521


4.7666


! 23.7378


5.3464


97


11.324t)


3.6278


13.7206


4.3523


16.0855


5.0526


18.3914


5.7307


98


7.6968


3.7729


9.3683


4.5699


11.0329


5.3558


12.6707


6.1311


99


3.9239


3.9239


4.7984


4.7984


5.6771


5.6771


j 6.5496


6.5496


100


0.0000




0.0000




0.0000




0.0000






100.0000


100.0000


100.0000


lOO.OOOO



VALUATION OF PUBLIC UTILITIES



1557



APPENDIX II.

Some Examples of the
Expectation of Life of So-Called Permanent Structures.

When one examines records of the life of different kinds of so-called
permanent structures, the actual life of such structures is frequently
found to be much shorter than the life usually estimated, and probably
much shorter than was anticipated when the works were new. For
the purpose of illustration, this subject has been investigated along
two lines: (a) the actual life of railway stations, and especially of
terminal stations; (b) the life of water-works sources, reservoirs, and
pumping stations.

TABLE 5. — Life of Eailway Stations.



Location.




Remarks.



Grand Central Station and Predecessors, New York City,



241 Bowery, at Prince Street

Tryon Row (Municipal Building)

Fourth Avenue and Twenty-sixth Street (Madison (
Square Garden) t

Forty-second Street

Forty-second Street. Extensive enlargement

Forty-second Street Station. Entirely remodeled /

and three stories added for offices t

Construction of new terminal started

Present station first used for electric service

Present station in full use




Boston and Albany Eailroad, Albany, N. Y.



Wooden building at Colonie and Broadway.
Brick and stone building at Maiden Lane. . .
Existing stone station



1866 (^
1873
1900 1




Boston and Albany Eailroad, Boston, Mass.



Original station

Kneeland Street Station

South Station (Union Station) .



History between
these dates not
known.



Boston and Providence Eailroad, Boston, Mass.


Original station


1834

1874 1
1899 \


25


History not


Park Square Station


known.


South Station









1558 VALUATION OF PUBLIC UTILITIES

TABLE 5. — Life of Eailway Stations. — (Continued.)



Location.



Year when


Life,


built or


in


enlarged.


years.



New York and New England Eaileoad, Boston, Mass.



Original station

Station burned and rebuilt

Station extensively remodeled.



South Station.



1872 )
1880 i

1893 f



Causeway Street Station

Station burned and replaced by brick building
North Station



1854
1863
1893



Remarks.



Boston and Maine Railroad, Boston, Mass.


Havmarket Square Station


1846 1
1893 1


47




North Station (Union Station)








Eastern Railroad, Boston, Mass.



FiTCHBURG Railroad, Boston, Mass.



Causeway Street Station .
North Station



1848 I
1893 f



Boston and Lowell Railroad, Boston, Mass.



Minot Street Station

Causeway Street Station

Causeway Street Station rebuilt

Merged into North Station, with minor alterations. .



1835 I

1852 )'

1873 (

1893 *



Boston and Albany Railroad, Worcester, Mass.


Original station 1835


36


History not


Union Station 1875 1

New Union Station 1911 f


known.






Average life of all stations


24









The Forty-second Street Station, in New York City, although cred-
ited with a total life of 34 years, had that length of life only for the
part built in 1883. The extensive enlargement in 1884 had a life of
23 years and the remodeled station of 1899, had a life of but 8 years.



VALUATION OF PUBLIC UTILITIES



1559



Life of Water-Works Structures.

The average life of the sources of water supply given in Table
6 was shortened by the introduction of a general system of water
supply for the Metropolitan District, which made the further use of
small local supplies undesirable.

Lake Cochituate, the original source of supply of Boston, has
been in use 65 years, and the Sudbury River, the second source of
supply of the city, has been in use 36 years, but both these sources
are now used only to a limited extent to supplement, when necessary,
the supply from the Wachusett Reservoir, the newest source.

TABLE 6. — Sources of Supply.
Massachusetts Metropolitan Water District.



Source.



Period.
Years.



Life,
in

years.



Remarks.



Boston, Mystic Lake source, supplying
12 000 000 gal. daily in the last year of its



life.



Maiden, Spot Pond

Maiden, ground-water source

Quincy, ground- water source

Quinoy, storage reservoir

Hyde Park, ground-water source, near Nepon-

set River

Hyde Park, ground-water source, near Mother

Brook

Medford, Spot Pond

Medf ord, storage reservoir

Revere, ground-water source in town

Revere, ground-water source in Cliftondale.. .

?4elrose, Spot Pond

Watertown, ground- water source

Arlington, storage reservoir

Arlington, ground-water source

Swampscott, ground-water source

Lexington, ground-water source

Lexington, storage reservoir



Average.



V 1864-1898

1870-1898
1890-1900
1884-1898
1888-1898

[ 1885-1913

[ 1899-1912

1870-1898
1894-1899
1884-1898
1891-1899
1870-1898
1885-1898
1873-1899
189.5-1900
1885-1899
1884-1903
1894-1903



Abandoned on ac-
count of increasing
pollution.



Reservoirs.

At the time of the completion of the original works supplying
Boston, in 1848, there was a reservoir of 23 acres in Brookline at the
end of the brick aqueduct. The pipes from this reservoir led to three
distributing reservoirs: one of them, on Beacon Hill in Boston, was
a large elevated masonry reservoir supported by arches; the other
two were earthen reservoirs on hills in South Boston and East Boston.

The Brookline Reservoir lost a large part of its value at the end
of 22 years, when it was superseded by a larger reservoir, but it had
a life of 52 years before its use was discontinued. The use of Beacon
Hill Reservoir was discontinued in 23 years; of the South Boston



1560



VALUATION OF PUBLIC UTILITIES



Reservoir in 24 years; and of the East Boston Reservoir, except for
the purpose of emergency use, in 32 years.

As in the case of the sources of supply, the life of pumping stations
in the Massachusetts Metropolitan Water District, has, in many cases,
been shortened by the introduction of a general system of supply. The
oldest of the five existing pumping stations in this district was built
26 years ago, and the building was extended 11 years after it was built.

A study of other water systems shows that sources, pumping sta-
tions, reservoirs and other works are frequently abandoned for various
reasons, such as the pollution of sources, the growth of population at
higher elevations than those originally provided for, and the general im-
provement and enlargement of the water system to meet changing con-
ditions.

An instance of an extremely short life of a reservoir and pumping
station was observed in connection with a valuation for rate-making
made in 1909. The rates in question were those of 1904 and 1905.
The pumping station and reservoir did not appear on the inventory
for 1904, because they had not then been built. They did appear
on the inventory for 1905, but could not be seen by the appraiser in
1909 because they had been superseded and removed. The cause of
the short life was a great influx of population which settled on elevated
land and required a more complete system of high-service works.

TABLE 7. — Pumping Stations.



Period.
Years.



Life, in
years.



Boston, original high service

Old East Boston

New East Boston

West Roxbury

mv^tio i Worthington Pump

Mystic ^ Leavitt Pump*

Somerville

Maiden, Spot Pond Station

Maiden, Webster Park Station

Chelsea

Everett

Quincy

Hyde Park, Neponset River Station .
Hyde Park, Mother Brook Station..

Medford, Spot Pond Station

Medford, Reservoir Station

Revere, Town Station

Revere, Cliftondale Station

Melrose

Watertown

Arlington

S wampscott

Lexington



18T0-18H8
1880-1889
1889-1898
1886-1913
186-1-1898
1896-1898
1890-1900
1883-1898
1800-1900
1886-1900
1888-1899
1884-1898
1885-1912
1899-1912
1892-1898
1894-1899
1884-1898
1891-1899
1886-1899
1885-1898
1895-1900
1885-1899
1884-1903



•This pumping engine was transferred to another pumping station when the Mystic
Station was abandoned.



VALUATION OF PUBLIC UTILITIES



1561



On the other hand it is not to be inferred from Table 6, that the
average life of sources of water supply is but 17 years, or from Table
7, that the average life of pumping stations is but 14 years — for the
life history of the majority of water-works will show that such is not
the case. These examples have been cited merely to indicate that
functional depreciation is an active force to be considered and given
such practical, weight as circumstances and experience may indicate
to be fair.

Thus, by comparison with Table 7, there might be cited the
experience of the Spring "Valley Water Company, of San Francisco,
Cal. Out of eight pumping stations (excluding the centrifugal booster
and ground-water supply stations, recently erected and still in service),
all but one are in active service — and this one was an emergency
station, and not one of permanent construction. The age of the
oldest station is about 30 years, the mean age of the investment in
the eight stations, 15 years.

Table 8 is a statement of the pumps in these stations.



Table 8.



Fly-vheel pumps.



Black Point 1-30 years.

" " 2-22 "

Belmont. ...'.['.['.'.'.'.'.'.'.'.'.'. '.'.'.'.'.'.'.'.'. 2-28 "

3-15 "

Merced 2-25 '•

Millbrae 1-18 "

Central 1-18 "

Clarendon 1-15



Direct-acting pumps.



Ocean View 2-18 years.

Precita 1-17 "

" 1-8 "

Centrifugal pumps.

Ravenswood 1- 4 years.

Pleasanton 1-3 "

1- 7 "

Crystal Springs .3-3 '•



No pumps have been discarded, except three small double-acting
low-duty pumps at Bald Hill emergency station, used in two or three
dry years for a few months only.

This comparison is made merely to indicate that each problem
must be thoroughly studied in the light of the local past, present,
and probable future conditions.



1563



VALUATIOX OF PUBLIC UTILITIES



APPEIS^DIX III.

Some Examples of Actual Overhead Cost.

In presenting these data as to actual overhead cost, the Com-
mittee desires to lay stress on the need of using all such figures with
caution. Items entering into overhead cost of different and similar
works are rarely alike, and many of the expenses, and even classes
of expense, incurred on one piece of work, might not be incurred on
another. It is impossible to forecast all the conditions and items
of overhead cost which will develop on any work. Were it otherwise,
no separate group of overhead cost would be necessary, for every
expense would be included in the unit costs.

Experience has shown, however, that indeterminate or indetermin-
able expenses always occur, and in such amount that they frequently
aggregate like, or similar, percentages of fixed unit costs. Hence, the
mere amount of those percentages, developed on other works, has a
bearing on the problem. Their segregation aids in forecasting
probable developments the more accurately, and they furnish a back-
ground of comparative experience which is useful.

Moreover, in valuing properties, years after their construction,
grave uncertainties generally arise as to the conditions which actually
developed during the construction of these works, and records are
virtually never in sufficient detail to eliminate them. Therefore,
the evaluator, as the designing and constructing engineer, must
make reasonable allowance, to cover the effect of these xmcertainties,
if justice is to be done.

To the evaluator, the records of greatest value are those developed
on work, with all the details, conditions, and surroundings of which
he is personally familiar, as these he is in a position to use most
intelligently as a yard-stick, and is least likely to misapply. The
evaluator should not attempt to figure the value of property with
the construction costs of which he is not familiar.

With reference to the data submitted, the details presented to
the Committee were so voluminous as to be impracticable of publication.

(a). — Examples Showing Cumulative Engineering Costs, with

Varying Volumes of Work.
Compiled from printed reports, under the supervision of Alfred

Craven, M. Am. Soc. C. E.



Year.


New York State Barge


Board of Water Supply-


Canal.


New York Aqueduct.


1905


ToOJj-




1906


98


167.0O/O


1907


40


174.0


1908


25


81.3


1909


14


32.9


1910


13


19.2


1911


9


14.5


1912


9


12.5


1913


9


11.86



VALUATION OF PUBLIC UTILITIES



1563

















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1568



VALUATION OF PUBLIC UTILITIES



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Online LibraryAmerican Society of Civil EngineersTransactions of the American Society of Civil Engineers (Volume 81) → online text (page 141 of 167)