,,american ,,society ,,of ,,civil       
,,engineers  ,,instituted #aheb         
,,transactions  ,paper ,no4 #aagf       
,,reinforced ,,concrete ,,pier          
,,construction4  ,,by ,,eugene ,,klapp1 
,m4 ,,am4 ,,soc4 ,c4 ,e4  ,,with        
,,discussion ,,by ,,messrs4 ,,william   
,,arthur ,,payne1 ,,and ,,eugene        
,,klapp4     ,a private yacht pier1     
built near ,glen ,cove1 ,long ,island1  
has brought out a few points which may  
be of interest4 ,it is an example of a  
small engineering structure1 which1     
though of no great moment in itself1    
illustrates the adoption of means to an 
end that may be capable of very great   
extension4  ,the problem1 as submitted  
to the writer1 was to construct a yacht 
landing at ,east ,island1 on the exposed
 south shore of ,long ,island ,sound1 in
 connection with the construction at    
that point of an elaborate country      
residence4 ,the slope of the beach at   
this point is very gradual1 and it was  
specified that there should be a depth  

of at least #d ft4 of water at low tide4
 ,soundings indicated that this         
necessitated a pier #cjj ft4 long4 ,it  
was further specified that the pier     
should be to some extent in keeping with
 the scale of the place being created   
there1 and that a wooden pile structure 
would not be acceptable4 ,besides these 
esthetic conditions1 wooden piles were  
rejected because the teredo1 in this    
part of the ,sound1 is very active4 ,at 
the same time1 the owner did not care to
 incur the expense of a masonry pier of 
the size involved4 ,also1 it was desired
 to unload on the pier all material for 
the house and grounds during            
construction1 and coal and other        
supplies thereafter1 thus necessitating 
a pier wide enough to allow access for a
 cart and horse and to provide room for 
turning at the pier head4               
,illustration3 ,,plate ,,xxx4--,,yacht  
,,pier ,,near ,,glen ,,cove1 ,n4 ,y4    
,comparative designs and estimates were 
prepared for 7a7 a pier of ordinary     

construction1 but with creosoted piles2 
7b7 a concrete pier on concrete piles2  
and 7c7 for a series of concrete piers  
with wooden bridge connections4 ,the    
latter plan was very much the best in   
appearance1 and the calculated cost was 
less than that of the pier of concrete  
piles1 and only slightly more than that 
of creosoted piles1 the latter being    
only of a temporary nature in any case1 
as it has been found that the protection
 afforded by creosote against the teredo
 is not permanent4  ,at this point on   
the ,sound the mean range of the tide is
 about #h ft41 and it was determined    
that at least #e ft4 above mean high    
water would be required to make the     
underside of the dock safe from wave    
action4 ,there is a northeast exposure1 
with a long reach across the ,sound1 and
 the seas at times become quite heavy4  
,these considerations1 together with #d 
ft4 of water at low tide and from #b to 
#c ft4 of toe-hold in the beach1        
required the outer caissons to be at    

least #bj ft4 high4  ,to construct such 
piers in the ordinary manner behind     
coffer-dams1 and in such an exposed     
location1 was to involve expenditure far
 beyond that which the owner cared to   
incur4 ,the writer's attention had      
shortly before been called to the       
successful use of reinforced concrete   
caissons on the ,great ,lakes for       
breakwater construction1 by ,major ,w4  
,v4 ,judson1 ,m4 ,am4 ,soc4 ,c4 ,e41 and
 under patents held by that officer4 ,it
 seemed that here was a solution of the 
problem4 ,these caissons are constructed
 on the shore1 preferably immediately   
adjoining the work4 ,after thorough     
inspection and seasoning1 they are      
usually launched in a manner somewhat   
similar to a boat1 are towed into       
position1 sunk in place1 and then filled
 with rip-rap4  ,in this case what was  
needed was a structure that could be    
constructed safely and cheaply in the   
air1 could then be allowed to harden    
thoroughly1 and could finally be placed 

in accurate position4 ,the weights to be
 supported were not great1 the beach was
 good gravel and sand1 fairly level1    
and1 under favorable circumstances of   
good weather1 the placing of the        
caissons promised to be a simple matter4
 ,therefore1 detailed plans were        
prepared for this structure4  ,an effort
 was made to preserve some element of   
the yachting idea in the design1 and    
bow-string trusses1 being merely        
enlarged gang planks1 were used to      
connect the caissons4  ,the pier was    
originally laid out as a letter ,l1 with
 a main leg of #cjj ft4 and a short leg 
of #cf ft4 ,the pier head consisted of  
eight caissons in close contact1 and was
 intended to form a breakwater1 in the  
angle of which1 and protected from the  
wave action1 was to be moored the float 
and boat landing4 ,after the first bids 
were received1 the owner wished to      
reduce the cost1 and every other caisson
 in the pier head was omitted1 so that1 
as built1 the pier contains eight       

caissons and five #ec-;ft4 trusses4 ,the
 caissons supporting the trusses are #h 
ft4 wide and #ab ft4 long1 and those in 
the pier head are #ab by #ab ft4 ,on    
account of the shoal water and the great
 height of the outer caissons in        
comparison with their cross-section1 it 
seemed advisable to mould them in two   
sections4 ,the reinforcement in the side
 walls consisted of round #a_/b-;in4    
rods horizontally1 and #c_/h-;in4 rods  
vertically1 spaced as shown on ,fig4 #a1
 together with cross-diaphragms as      
indicated4  ,the caissons were          
reinforced for exterior pressures1 which
 were to be expected during the         
launching and towing into position1 and 
also for interior pressures1 which were 
to be expected at low tide1 when the    
water pressure would be nothing1 but the
 filling of the caissons would be       
effective4 ,the corners were reinforced 
and enlarged4 ,in order to secure a     
proper bedding into the sand foundation1
 a #ab-;in4 lip was allowed to project  

all around the caisson below the bottom4
 ,in the bottom there was cast a #c-;in4
 hole1 and this was closed by a plug    
while the lower section was being towed 
into place4  ,the question of the effect
 of sea water on the concrete was given 
much thought4 ,the writer is unable to  
find any authoritative opinions on this 
subject which are not directly          
controverted by equally authoritative   
opinions of a diametrically opposite    
nature4 ,he thinks it is a question that
 this ,society might well undertake to  
investigate promptly and thoroughly4    
,there can be no question that there are
 many distressing instances of failures 
due to the action of sea water and frost
 on concrete1 and that many able and    
experienced engineers in charge of the  
engineering departments of the great    
transportation companies have simply    
crossed concrete off their list of      
available materials when it comes to    
marine construction4 ,it is a subject   
too large in itself to be discussed as  

subsidiary to a minor structure like the
 one herein described1 and though many  
have rejected concrete under these      
conditions1 other engineers equally     
conservative are using it freely and    
without fear4  ,the writer consulted    
with his partner and others at some     
length1 and1 considering all the        
advantages to accrue by the use of these
 concrete caissons1 decided to do so    
after taking all known precautions4     
,illustration3 ,,fig4 #a4  ,these       
precautions consisted in3  ,first1 the  
use of cement in which the chemical     
constituents were limited as follows3   
,it was specified that the cement should
 not contain more than #a4ge of         
anhydrous sulphuric acid 7,,so#c7 nor   
more than #c of magnesia 7,mg,o72 also  
that no addition greater than #c should 
have been made to the ingredients making
 up the cement subsequent to            
calcination4  ,secondly1 to secure by   
careful inspection the most completely  
homogeneous mixture possible1 with      

especial care in the density of the     
outer skin of the caissons4  ,thirdly1 a
 prolonged seasoning process before the 
new concrete should be immersed in the  
sea water4  ,in addition to these       
well-known precautions1 it was decided  
to try the addition to the cement of a  
chemical element that should make with  
the free lime in the cement a more      
stable and indissoluble chemical        
combination than is offered by the      
ordinary form of ,portland cement4 ,this
 was furnished by the patent compound   
known as ,toxement1 which is claimed by 
the inventor to be a resinate of calcium
 and silicate of alumina1 which         
generates a resinate of lime and a      
silicate of alumina in crystalline form4
 ,it is further claimed that each of    
these materials is insoluble in sodium  
chloride and sodium sulphate1 #c        
solution4 ,it was used in all the       
caissons1 excepting ,nos4 #a and #b1 in 
the proportions of #b lb4 of ,toxement  
to each #ajj lb4 of cement4 ,the first  

two caissons were not thus treated1 and 
will be held under close observation and
 comparison with the others1 which were 
treated with this compound4  ,the       
mixture used was one of cement          
7,pennsylvania brand71 two of sand1 and 
four of gravel4 ,the sand and gravel    
were from the nearby ,cow ,bay supply1  
and screened and washed4 ,none of the   
gravel was larger than #a_/b in41       
grading down from that to very coarse   
sand4 ,the sand was also run-of-bank1   
and very well graded4  ,the caissons1   
after being placed1 were filled with    
sand and gravel from the adjoining beach
 up to about mean high-water mark1 and  
the edges outside all around were       
protected from tidal and wave scour by  
rip-rap of one man stone4  ,the trusses 
were constructed on a radius of #cd ft41
 with #h by #h-;in4 chords1 #f by       
#f-;in4 posts1 and #a-;in4 rods4 ,the   
loading was figured as a loaded coal    
cart plus #ajj lb4 per ft4 ,all lumber  
was clear yellow pine1 except the floor1

 which was clear white oak4 ,the pipe   
rail and all bolts below the roadway    
level1 and thus subject to frequent     
wettings by salt water1 were of         
galvanized iron4 ,the trusses were set  
#i ft4 #i in4 apart on centers1 giving a
 clear opening of #h ft4 between the    
wheel guards under the hand-rails4 ,the 
fender piles were creosoted4 ,the float 
was #ah ft4 long and #ab ft4 wide4  ,a  
contract was let to the ,snare and      
,triest ,company1 and work was commenced
 early in ,august1 #aiji4 ,the first    
caisson was poured early in ,september1 
and the last about the beginning of     
,october4  ,the caissons were all cast  
standing on parallel skids at about mean
 high water4 ,it was first intended to  
construct a small marine railroad and   
launch the caissons in that manner1     
rolling them along the skids to the head
 of the marine railway4 ,this plan was  
abandoned1 however1 and by sending in at
 high tide a powerful derrick scow1 many
 of the caissons were lifted bodily from

 their position and set down in the     
water1 towed to place and sunk in       
position1 while the others1 mostly the  
upper sections1 were lifted to the deck 
of the scow and placed directly from    
there in their final position4 ,there   
was not much difficulty in getting them 
to settle down to a proper bearing4     
,provision had been made for jetting1 if
 necessary1 but it was not used4 ,in    
setting ,caisson ,no4 #b a nest of      
boulders was encountered1 and a diver   
was employed to clear away and level up 
the foundation4 ,the spacing was        
accomplished by a float consisting of   
two #ab by #ab-;in4 timbers1 latticed   
apart1 and of just sufficient length to 
cover the clear distance between the    
caissons4 ,the first caissons being     
properly set inshore1 the float was sent
 out1 guyed back to the shore1 and      
brought up against the outer edge of the
 set caisson4 ,the next caisson was then
 towed out1 set against the floating    
spacer1 and sunk in position4 ,there was

 some little trouble in plumbing the    
caissons1 but1 by excavating with an    
orange-peel bucket close to the high    
side and depositing the material against
 the low side1 they were all readily    
brought to a sufficiently vertical and  
level position to be unnoticed by       
sighting along the edge from the shore4 
,the trusses were all constructed in the
 contractor's yard at ,bridgeport1 and  
were towed across the ,sound on a scow4 
,they were set up and braced temporarily
 by the derrick boat1 and then the floor
 and deck were constructed in place4    
,on ,december #bfth1 #aiji1 a storm of  
unusual violence--unequaled in fact for 
many years--swept over the ,sound from  
the northeast2 the waves beat over the  
pier and broke loose some floor planks  
which had been only tacked in position1 
but otherwise did no damage1 and did not
 shift the caissons in the least4 ,the  
same storm partly destroyed a pier of   
substantial construction less than a    
mile from the one in question4          

,unfortunately1 the work was let so late
 in the summer1 and the restrictions as 
to seasoning the concrete were enforced 
so rigidly1 that the work of setting the
 caissons could not be commenced until  
,november #aath1 thus the entire        
construction was forced into the very   
bad weather of the late fall and early  
winter4 ,as this involved very rough    
water and much snow and wind1 the work  
was greatly delayed1 and was not        
completed until the middle of ,january4 
,the cost of the entire dock was about  
#ad1jjj4  ,the writer believes that the 
cost was much less than for masonry     
piers by any other method of            
construction1 under the existing        
circumstances of wind1 tide1 and        
exposure4  ,it would seem that for many 
highway bridges of short span1          
causeways1 and similar structures1 the  
use of similar caissons would prove     
economical and permanent1 and that they 
might be used very largely to the       
exclusion of cribwork1 which1 after a   

decade or so1 becomes a source of       
constant maintenance charges1 besides   
never presenting an attractive          
appearance4 ,finally1 in bridges        
requiring the most rigid foundations1   
these caissons might readily be used as 
substitutes for open wooden caissons1   
sunk on a prepared foundation of        
whatever nature1 and still be capable of
 incorporation into the finished        
structure4     ,,discussion   ,,william 
,,arthur ,,payne1 ,m4 ,,am4 ,,soc4 ,c4  
,e4 7by letter74--,on the arrival of the
 first barge load of brick1 to be used  
in building a residence on the estate to
 which this pier belongs1 a severe      
northwest wind blew for two days1 after 
the boat was moored alongside1 directly 
against the head of the pier and the    
side of the boat4 ,the effect on the    
pier was to crush the fender piles and  
cause a settlement of one of the        
caissons at the pier head on the west   
end4 ,the caisson was knocked slightly  
out of alignment1 and a settlement      

toward the west was observable4  ,the   
writer believes that this was caused by 
the pounding of the brick barge on the  
sand bottom on which the caissons rest1 
during half tide1 the boat being raised 
from the bottom on a roller1 and        
striking when the roller had passed4 ,in
 order to protect the pier and avoid the
 bumping of barges against it1 three    
groups of piles were driven about #h ft4
 beyond the end1 a secondary platform   
was built between these and the stringer
 of the pier1 and arranged so that it   
would slide on the stringer in case of  
movement of the piles4 ,this secondary  
platform is particularly advantageous in
 the handling of material1 as the height
 of the dock was found to be excessive  
for passing up brick and cement4 ,for   
handling material after it is deposited 
on the dock1 an industrial railroad has 
been built4 ,at the shore end of this   
railroad1 brick and cement are dumped   
into wagons1 in which they are carried  
up the hill to the house4   ,,eugene    

,,klapp1 ,m4 ,,am4 ,,soc4 ,c4 ,e4 7by   
letter74--,the injury done to the piers1
 as reported by ,mr4 ,payne1 is not to  
be wondered at4 ,the pier was primarily 
built for a yacht landing1 and1 on      
account of the shoal water conditions1  
excepting at extreme high tide1 it was  
mostly to be used by tenders and        
launches from larger yachts4 ,it was    
thought that at high water the large    
steam yachts might be able to come      
alongside4  ,provision was not made for 
tying up to the dock a heavily loaded   
brick scow and allowing it to remain    
there through rough weather4  ,the      
building of the secondary fender piles1 
during the temporary use of the dock for
 unloading building material1 will      
doubtless prevent further damage4