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NORA lORE- BREE ZF ire 
Manchester’s Concrete Standpipe 
T the special Town Meeting in 
Manchester last week (Nov. 
17) to act on the report of the 
special committee on the standpipe 
investigation, Raymond C. Allen, 
civil engineer, spoke at length on 
the situation, and we print his re- 
marks—which he read—in full. 
The whole discussion, we might 
add, is brought about because of 
leaks in the concrete structure, and 
the growing dissention lead up to 
the appointment of a committee 
last March to “investigate.” The 
committee presented their report in 
printed form, but the “‘investiga- 
tion” apparently revealed nothing 
of a startling nature. 
By Raymonp C. ALLEN, CoE. 
HE installation of the. additional 
water supply in 1909 involved 
the construction of a new reservoir 
or standpipe which should have a 
capacity of about one million gallons 
and which should have its high water 
line at an elevation of 250 feet above 
mean low water and be capable of being 
extended so that it might finally have 
a high water elevation of 275 feet 
above mean low water. This was in 
accordance with the recommendation 
of Mr. Desmond FitzGerald, Consult- 
ing Engineer who made a report to the 
town in October, 1907. 
The construction of this additional 
supply devolved upon the Board of 
Water Commissioners of the year 1908 
and 1909. In considering this ques- 
tion at that time, the Water GCommis- 
sioners gave the matter careful study 
and found after investigation, that 1% 
would be more economical to build the 
structure to the height of 275 feet 
above low water rather than to build 
a structure and later extend it to an 
additional 25 feet, as the cost of add- 
ing this 25 feet would be out of all 
proportion to the cost of building the 
complete structure at once. 
This having been determined, the 
Water Board had specifications pre- 
pared covering the construction of a 
steel standpipe 60 feet in diameter and 
holding 70 feet of water. While these 
specifications were being prepared and 
figures being obtained upon them, the 
attention of the Board was forcibly 
drawn to the large number of failures 
of steel and wrought iron standpipes, 
some 23 failures having been reported 
in a period of nine years closely pre- 
ceeding 1909. These failures upon in- 
vestigation were found to be due in 
some cases to faulty foundations and 
improper material. In many cases, 
however, and particularly in large 
tanks and exposed locations, the fail- 
ures had been due to wind action and 
particularly to the action of ice with- 
in the standpipe. This latter action 
was found to be particularly difficult 
to guard against and was the cause of 
a number of failures where all other 
conditions appeared to have been: well 
guarded against. In gathering data 
bearing upon the above failures the 
attention of the Board was forcibly 
drawn to a number of re-enforced 
concrete standpipes which at that time 
had been built and appeared to be 
very satisfactory. Among these were 
stroctures at Waltham, Attleboro, Mil- 
ford, Ohio, Fort Revere and Bonds- 
ville in Massachusetts, Lenoir, North 
Carolina, New Haven, Connecticut, 
and Senora in Mexico. The height of 
these structures varied from 20 feet to 
102 feet and the diameters from 10 feet 
to 100 feet. Their contents varied 
from 25,000 gallons to 2,000,000. The 
general result obtained from these 
standpipes up to that time was found 
to be excellent. The one at Attleboro, 
however, 100 feet in height, showing 
the least satisfactory results. Visits +o 
several of these were made and in all 
cases those in authority professed 
themselves well satisfied with the 
structures and said from their experi- 
ence with them, that if they were to 
build again, they would use the same 
material. 
Ii is generally conceded that in the 
construction of a metal standpipe the 
best wrought iron is a more desirable 
material for use than steel. This was 
particularly the case up to a decade or 
so ago as up to that time the manu- 
facture of steel had not reached the 
efficient stage which it has since at- 
tained. It has become increasingly 
difficult to obtain the best wrought- 
iron although material bearing that 
name can be obtained. A refined steel 
similar to what is known as flange 
steel is considered an excellent ma- 
terial of which to build a standpipe 
and where any doubt exists as to the 
character of wrought iron which can 
be obtained, is probably the safer ma- 
terial to use. 
In the consideration of the structure 
to be built, however, and in the com- 
parison of a metal standpipe with one 
of re-enforced concrete, the question 
of wrought iron or steel was not a 
very important factor. The two struc- 
tures were compared upon two main 
points, the first that of safety and the 
second of maintenance, In view of 
the failures of standpipes above re- 
ferred to, much interesting literature of © 
which is available, grave doubts arose 
in the minds of the Commissioners as 
to the safety of a steel structure of the 
large size proposed and as to the pos- 
sibility of effectively guarding against 
them. These doubts were shared by 
several competent authorities who 
were consulted. There was also a 
doubt in the Commissioners’ minds and 
in my own as to the possible action of 
frost upon seepage from within the 
standpipe or upon moisture collecting 
on the outside and this point is dis- 
eussed by the Commissioners in their 
report for 1909, page 5. The experi- 
ence of the places above referred to, 
however, led the Commissioners and 
myself to believe that this source of 
danger was not to be feared. 
The Board then approached a de- 
cision in the matter with the strong 
and well founded belief that a metal 
standpipe presented certain possible 
features of weakness almost impossible 
to guard against, while a concrete 
seructure would be free from them. 
Proposals for structures both of 
metal and re-enforced concrete were 
widely advertised in the Engineeriny 
papers and the daily papers of Boston. 
Some 26 bidders from all over the 
country asked for specifications for the 
metal structure and 8 submitted bids, 
the lowest being about $24,000 and the 
highest a little over $35, 000. To both 
of these figures should be added about 
$4,000 for the construction of a sguit- 
able foundation making the lowest bid 
about $28,000. Several concerns *e- 
quested specifications for a re-enforced 
concrete standpipe and two submitted 
bids, the lowest being $33,290 and the 
highest being a little over $43,000. 
Both these fiures included the found- 
ation. 
In view of the fact that a million 
gallons capacity was one of the gov- 
erning factors of the new structure 
and with a high water level at eleva- 
tion 275, and this result could be ob- 
tained by the construction of a stand- 
pipe having a diameter of 50 feet, it 
was decided to obtain figures from ‘the 
two lowest bidders of the different 
structures upon this basis. The fig- 
ures resulting from this revision were 
about $21,000 for the metal standpipe 
and $29,150 for the re-enforced con- 
erete standpip>. 
In the comparison of these two 
structures the maintenance of the 
metal structure called for careful con- 
sideration in addition to the consider- 
ation to be given the possible danger 
from wind and ice. The best author- 
ities upon the proper maintenance of 
metal standpipes advise that for the 
best results such structures should be 
painted both inside and outside at in- 
tervals generally not exceeding three 
years. The last time the old stand- 
pipe in Manchester was painted within 
and without appears from the records 
to have been in 1906 and was done at 
that time at a cost of $520.40 plus the 
cost not readily obtainable of con- 
tinous pumping during the time in 
Which the painting was carried on. 
Due to the greater size of the pro- 
posed structure and its much greater 
inaccessibility, it was estimated that 
it would cost at least $1200 to paint 
this structure in the same way. If 
this were done every three years, there 
would be an annual charge of main- 
tenance of about #400 plus the extra 
cost of continuous pumping during the 
work. It was believed at that time 
that the re-enforced concrete structure 
would require no maintenance and this 
was a fair assumption upon the _ in- 
formation then available. Capitali- 
zing this annual cost of the mainten- 
ance of the metal structure at any 
reasonable rate of interest, there seem- 
ed no fair reason to doubt that the 
concrete structure would be in the end 
the more economical, and the Board 
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