Permanent pier piling

A permanent pier piling for use in docks and the like in a body of water whereby an antifreeze solution within the piling circulates to distribute latent ground heat from the lower portion of the piling to the upper portion of the piling to maintain a fluid interface between the piling and the ice during the winter season.

BACKGROUND OF THE INVENTION 
This application relates to a device for protecting pier pilings and 
moorings and, more particularly, to a device for preventing the formation 
of ice about a pier piling or mooring. 
Docks and the pilings supporting docks are generally subject to a seasonal 
existence, that is, they must be disassembled and withdrawn from the lake 
annually approaching winter and reconstructed each spring after the 
retreat of the cold weather. The phenomenom of seasonal freezing of bodies 
of water in northern climates causes ice to freeze about its top surface 
and seize any object on the water surface. Thus, the piling supports of 
docks and other lake-front structures and the moorings of marinas which 
may be immersed in the water in the winter are firmly gripped about their 
circumferences by the layer of ice thus formed on the top of the water. 
As in warmer weather, the level of the body of water fluctuates widely 
during winter and does not remain at a constant level even while frozen, 
due to a variety of natural causes. With a change in the elevation of the 
ice, the firm grip which the ice retains about objects fixed in the body 
of water invariably causes the object to be dislodged upward from its 
ground support. In the case of pilings, the new upraised position in turn 
forces the dock or other structure supported by the piling to become 
warped and uneven to the extent that it is useless for bearing weight of 
any sort. In extreme cases, the pilings may be completely uprooted and the 
damage which is done to unprotected structures is an expensive annual 
problem. In the face of this certain rebuilding of a dock each year, dock 
owners customarily disassemble their dock each year, reusing the dock 
material the following year in order to avoid the cost of new material. 
This arduous task has led to the use by some of floating docks and 
floating moorings in marinas which are generally anchored in a rather 
loose fashion. The relative instability of these substitutes are tolerated 
only because of the unacceptability of pilings and, up to now, the 
unavailability of permanent pilings for docks and moorings. 
Protective apparatus have also been used to isolate the piling from direct 
contact with the ice. In one instance, a sleeve was placed about the 
piling, the sleeve being freely moveable up and down the piling to thus 
insulate the piling from the changes in the level of the ice. While these 
protective sleeves worked satisfactorily for a short time, the battering 
absorbed by these sleeves soon deteriorated their effectiveness. 
SUMMARY OF THE INVENTION 
These and other objects are obtained in accordance with the present 
invention wherein there are provided permanent support pilings for a dock 
or moorings. These support pilings comprise conventional thick walled, 
cast iron, hollow piping sealed fluid tightly at one end. This sealed end 
is preferably pointed for easy driving into the bed of the water body. The 
piling is driven into the bed of the lake, river or other body of water in 
which it may be used and positioned at a desirable height above the 
surface of the water. The piling is of a length to extend to a depth below 
the frost line when driven into the water bed. A liquid or mixture of 
liquids known to have a freezing point or range below that of the lowest 
recorded temperature for the region in which the piling is being placed is 
introduced into the piling, reaching a height which will insure that the 
height of the liquid will always remain above that of the body of water. 
This liquid, or antifreeze solution as it is commonly known, may comprise 
a mixture of ethylene glycol and water, but, in any event, the prime 
characteristics of the liquid should be that it is nonvolatile, 
noncorrosive and of low viscosity at the temperatures of use. The piling 
may be capped prior to affixing the dock surface. 
The antifreeze solution within the piling circulates, absorbing the latent 
heat of the bed of the water body through the piling wall, and, by natural 
convection currents the antifreeze solution rises to the upper surface 
portion of the liquid in the piling where it transfers its heat to the 
piling's environment, thereby keeping the area of water immediately 
adjacent the piling ice-free. The cooled antifreeze solution then reverses 
its direction and, continuing its circulation, descends to the lower 
depths of the pipe to renew the cycle. Due to the extension of the piling 
below the frost line, and, by virtue of the circulation of the antifreeze 
within the piling, the temperature of the antifreeze in the piling is kept 
above freezing, regardless of ambient conditions. Thus, the ice is 
precluded from forming about the piling and the piling is thereby left 
undisturbed by the changes of water levels due to natural occurrences. 
A nonfreezing liquid of nonvolatile characteristics, immiscible with the 
antifreeze solution and of lower density than the antifreeze solution, for 
example, an oil or kerosene, may also be introduced into the piling to 
provide an upper layer which will retard the evaporation of the antifreeze 
solution. 
SUMMARY OF THE INVENTION 
It is accordingly an object of the subject invention to provide a means for 
preventing ice from causing damage to a dock or mooring. 
A further object of the subject invention is to provide a permanent means 
of protecting pilings from the ravages and destructiveness of winter.

DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring now to FIG. 1, there is shown a dock 10 and a body of water 55. 
The dock 10 has a surface 12 supported by pilings 20. It should be 
understood that while the subject invention is shown in use for the 
support of a dock surface, any type mooring which may be used at marinas 
and the like to secure vessels or other waterborne objects, is considered 
within the scope of the subject invention. 
The piling 20 comprises a length of heavy walled cast iron piping of 
approximately 12 to 15 feet, and more in deep water areas. The piping 20 
has a closed end 22 and an open end 24 (FIG. 2). The closed end 22 is 
fluid-tightly sealed and preferably pointed to aid in driving it into the 
bed 45 of the water body. The piling 20 of the subject invention is driven 
into the bed 45 by conventionally known means, such as pile drivers and 
the like. The depth to which the piling must normally be driven to attain 
the desired support for the dock or for use as a mooring would generally 
be of a sufficient depth for the purposes of the subject invention, as 
will hereinafter be explained. 
Once the piling 22 is driven into the bed 45 of the body of water 55, a 
suitable antifreeze solution 35 is introduced into the piling 20. The 
amount of anitfreeze solution 35 in the piling should be sufficient to 
maintain a level above the high water level of the body of water. The 
antifreeze solution, as previously stated, should be of a noncorrosive and 
nonvolatile nature and capable of remaining fluid down to the lowest 
temperatures of the region where in use. Generally protection down to 
-30.degree. F. is sufficient, although the far northern latitudes may 
require a lower freezing point of the liquid. As the piling is 
contemplated to be of a permanent nature, the characteristics of the 
liquids within the piling become as important as the stresses and other 
phenomenom occurring outside by natural forces to the piling 20. Thus, 
while some solutions might have a particularly low viscosity and high 
thermal transfer properties, their corrosiveness may cause such damage to 
the interior of the piling as to destroy the structural integrity or allow 
the antifreeze solution to leak from the pipe, thereby diluting the 
effectiveness of the antifreeze solution, and, eventually allowing ice to 
form about the piling. 
A small amount of liquid 30, having a lower density than the density of the 
antifreeze solution 35 and sufficiently nonvolatile, such as oil or 
kerosene, may be also introduced into the piling 20 to provide an 
effective deterrent to evaporation of the antifreeze solution (FIG. 2). Of 
course, this lower density liquid 30 should not be miscible with the 
antifreeze solution 35. 
After the introduction of the liquids 30 and 35 into the piling, a cap 25 
may be placed on the piling and secured by suitable means such as a bolt 
and nut 26. This cap may have other bolts 28 integrally attached thereto 
to provide a means of securing the dock surface 12 to the mooring. While 
shown as being attached to the piling by nuts and bolts, any suitable 
means of securing the dock surface to the piling may be used. In this 
manner the introduction of foreign matter such as diluents or pebbles may 
be avoided. 
When installed as above, the antifreeze solution 35 within the piling 20, 
absorbs the latent ground heat of that portion of the water bed 45 which 
is above the freezing temperature of water. Care must be taken to drive 
the piling deep enough so that it extends below the freeze or frost line 
of the ground in that particular vicintiy. Further, the piling 20 must 
extend sufficiently below this frost line into the ground 45 so that 
sufficient thermal contact may be made between the piling 20 and the 
ground 45. This depth is generally attained in the normal depths to which 
pilings are driven. In extreme northern latitudes, it may be found 
necessary to drive the pilings to a greater than normal depth. The latent 
heat in the ground 45 is absorbed by the antifreeze solution 35 within the 
pipe. Due to the natural process of convection, the antifreeze solution 
then circulates within the piling 20 so that the portion of the antifreeze 
solution 35 holding the absorbed latent heat of the ground 45 rises to the 
upper layers of the antifreeze solution 35. By this natural circulation of 
the antifreeze solution 35 (depicted by arrows in FIG. 2), no permanent 
strata may develop within the piling 20 which would isolate a portion of 
the solution at the uppermost levels, thereby causing the temperature of 
the solution to fall below 32 degrees and enable the ice 50 to form about 
the piling 20. 
Thus, by the circulation of the antifreeze solution 35, the temperature of 
the piling 20 itself may be kept constantly above the freezing temperature 
of the water, thereby maintaining a fluid interface 32 with the ice 50 
(FIG. 3). The interface 32 absorbs enough heat from the piling to remain 
liquid, thereby insuring that the ice will not form about the piling 20. 
In this manner, the level of the body of water 55 and the ice 50 may 
fluctuate without affecting the piling 20. While the interface 32 has been 
given a certain dimension, it should be understood that it may at times 
comprise only a small gap between the piling and the ice, though 
sufficient to deny the ice contact with the piling 20. 
While the invention has been described with reference to a preferred 
embodiment, it will be understood by those skilled in the art that various 
changes may be made and equivalents may be substituted for elements 
thereof without departing from the scope of the invention. In addition, 
many modifications may be made to adapt a particular situation or material 
to the teachings of the invention without departing from the essential 
scope thereof. Therefore it is intended that the invention not be limited 
to the particular embodiment disclosed as the best mode contemplated for 
carrying out this invention, but that the invention will include all 
embodiments falling within the scope of the appended claims.