US3370432A

US3370432A - Ice protective sleeve for pilings

Info

Publication number: US3370432A
Application number: US476894A
Authority: US
Inventors: Roger M Butler; Leander B Simpson
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1965-08-03
Filing date: 1965-08-03
Publication date: 1968-02-27
Anticipated expiration: 1985-02-27

Description

Feb. 27, 1968 R. M. BUTLER ET AL 3,370,432

ICE PROTECTIVE SLEEVE FOR PILINGS Filed Aug. 5, 1965 United States Patent O 3,370,432 ICE PROTECTIVE SLEEVE FOR PILINGS Roger M. Butler, Janis Bumbulis, and' Leander B. Simpson, Sarnia, Ontario, Canada, assgnors to Esso Research and Engineering Company, a corporation of j Delaware Filed Aug. 3, 1965, Ser. No. 476,894 6 Claims. (Cl. til- 54) ABSTRACT OF THE DISCLSURE The present invention is directed towards providing apparatus and a method for preventing the gradual and almost universal jacking out of pilings subject to adverse winter environment. In accordance with the invention a tubular collar of a buoyant foam plastic material is positioned, surrounding and spaced from the piling. The interior annular space between the sleeve and the piling is lled with any suitable anti-freeze solution which is of a density less than Water and insoluble therein. In this way ice forming on the surface of the water and freezing will freeze tightly against the exterior surface of the protective sleeve; and when said ice lifts to the changes in the Water level, it will lift the s eeve and not the piling.

This invention relates to a novel method and means for the protection of pilings placed in water subject to freezing and to changes in level during the presence of surface ice. More particularly, the present invention relates to an improved method and means for isolating a piling from direct contact with ice forming on the surface of the body of water surrounding the piling.

In accordance with the invention, a tubular collar surrounding and spaced from the piling is supported relative either by buoyancy forces or by direct mechanical connection to the piling in a relationship to always be intersected by the water line. The interior annular space between the sleeve surrounding the piling and the piling is illed with any suitable antifreeze solution which is of a density less than Water and insoluble therewith. In this way, the ice forming on the surface of the water and freezing tightly against the exterior surface of the protective seeve, is effectively precluded from freezing against the piling. As the level of the surface of the water and associated ice chauves due to tide or normal variance of lake or river level, the sleeve will move along with the ice frozen thereto, but will be free to slide relative to the pi ing due to the nonfrozen antifreeze therebetween. The invention provides a novel and extremely simple means and method for preventing the gradual and almost universal jacking out of pilings subject to adverse winter environment.

Accordingly, a principal object of the invention is to provide a novel method and means for protecting pilings extending upwardly out of a body of water subject to freezing and changes in the surface level.

Another object of the invention is to provide an improved buoyantly supported piling protective sleeve.

Another object of the invention is to provide an irnproved offshore drilling platform for use in areas subject to large changes in tide which are also subject to extreme arctic temperatures.

A still further object of the invention is to provide a protective sleeve for pilings which is easy to manufacture, highly reliable in operation, simple in design and rugged in construction.

These and other objects and advantages of the invention will become apparent and the invention will be fully understood from the following description and drawings in which:

FIGURE 1 is a side elevation View of one embodiment of the invention showing portions in section;

FIGURE 2 is a view of an alternate form of the invention;

FIGURE 3 is a view similar to FIGURE 1 showing still another embodiment of the invention; and

FIGURE 4 is a view of the invention as it would be employed in combination with an oishore drilling platform.

Referring to the drawings, and to FIGURE l in particular, the protective sleeve 10 is positioned coaxially around a piling 2, extending through a body of water 14, and embedded at its lower end in the ground 16. The protective sleeve I is preferably annular in form but it will be readily understood that it need not be limited to any particular cross-sectional shape. The sleeve 10 includes an annular support means 1S in the form of a buoyant ring containing a sealed air space 20. An antifreeze solution 22 is provided between the inside of the sleeve 10 and the exterior surface of the piling 12. The antifreez 22 is of a density less than the surrounding water 14 and insoluble therewith. In this fashion, the antifreeze 22, which in one form of the invention has been a conventional oil, will not over a period of time dissipate into the surrounding Water to render the invention ineifective and also will not dissipate into the water to pollute the water.

In operation, as the surface of the water forms in an ice layer 24 and freezes tightly against the exterior walls of the sleeve 16 and the buoyancy ring 18, a corresponding freezing of the oil annulus 22 will not occur. Therefore, as the level of the water 14 and ice 24 raises or lowers due to tide or just normal river height change, the piling will be protected from the effect of the ice and will not be jacked upwardly as would be the case without the use o applicants invention. Prior to applicants invention, it was customary in small marinas to have a substantial degree of lifting of all the pilings during the course of a winter to the great expense in the springtime of repositioning the pilings to their desired vertical height to rmly embed them iu the sea floor.

Referring to FIGURE 2, a rnodied form of applicants novel protective device is shown. In FIGURE 2, the main body portion 26 of the protective sleeve is preferably made of a foam plastic material which is normally quite buoyant in water. To insure upright stability of this highly buoyant protective sleeve in its substantially coaxial position in the Water about the piling, an annular stabilizing weight 28 is provided about the lower portion of the sleeve 26. The buoyancy of the sleeve 26 versus the stabilizing weight of the ring 28 is so proportioned that the arrangement of FIGURE 2 will oat in the approximate same relative position with respect to the surface of the'water as the embodiment of the invention shown in FIGURE 1.

Referring to FIGURE 3, another form of the invention is shown wherein a sleeve 39 of steel or plasticmaterial is coaxially supported about a piling 12 by a pair of nails 34 driven into the piling. The nails 34 limit the extent to which the sleeve 30 may descend along the piling 12. As an alternate Way of fixing and limiting the position of the sleeve 30 relative to the piling 12, a pair of chains 32 may be employed. The chains 32 are affixed at their upper end to an upper portion of the piling while their lower ends are secured to the sleeve 30. In a preferred arrangement of FIGURE 3, a sleeve of 41/2 ft. length has been employed located with approximately 1 ft. above t-he waters surface. The height of the oil 22 approximated 2.5 ft. While the embodiment of the invention shown in FIGURE 3 is perfectly suitable for use in protecting pilings in bodies of water wherein the surface level stays relatively constant and varies between relatively small predetermined limits, it will readily be seen that should the surface level of the water body drop to any large extent prior to freezing, the sleeve would have to be of considerably extended axial length to remain operative. The oated buoyant embodiments of the invention shown in FlGURES 1 and 2, unlike FIG- URE 3, will compensate automatically for any changes in tne water level prior to freezing because of their buoyant nature. It will also be appreciated that, should it be Y, a conventional well drilling rig 40. At the surface of the water surrounding each of the `pilings 38 is a novel protective sleeve shown schematically at 10. This protective sleeve may be of either form of the invention shown in FIGURES l to 3 inclusive. lt has been found that in locations wherein offshore drilling rigs are ernployed that are subject to high tides and severe freezing such asexperienced in the Alaskan regions, a considerable amount of extra and normally unnecessary structural strength has to be designed into the supporting pilings 38 in order to withstand the anticipated Vice and tidal loads. By use of applicants invention to substantially and completely eliminate the risk of these ice loads on the pilings substantial reduction in design safety factor may @be employed in the construction of the drilling platform to thereby lower its overall cost and increase its margin of prot.

While several specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be under- V stood that the invention may be embodied otherwise without departing from such principles.

What is claimed is: Y

1. The method of isolating a piling from direct contact with ice forming on the surface of a vbody of Water surrounding said piling, comprising the steps of, surrounding said piling with an impervious tubular sleeve of buoyant .plastic foam material, said sleeve extending along the length of said piling above surface of said water, and having a predetermined interior dimension larger than the exterior dimension of said piling, maintaining/said sleeve in an upright position by a weighted annular stabilizing means aiixed around the exterior circumference of the bottom end of said sleeve, and filling a portion of the space between said piling and said sleeve with an antifreeze ksolution and below the Y of density less than said water and insoluble therewith.

2. The method of isolating a plurality of pilings of an offshore drilling platform from direct Contact with .ice forming on the surface of a body of water surrounding Vsaid platform, comprising the steps of surrounding each of said pilings with a spaced tubular sleeve of buoyant plastic foam material extending along the length of each of said pilings above and below the Asurface of said water, maintaining said sleeve in an upright position by a weighted annular stabilizing means affixed around the exterior circumference of the bottom end of said sleeve, and lling -a portion of the space between each of said pilings and'associated impervious member withan antifreeze solution of density less than said water and insoluble therewith.

3. Means for protecting a piling from direct contact with ice forming on the surface of a body of water surrounding said piling comprising, a tubular sleeveY of buoyant plastic foam material having a predetermined inside dimension substantially larger than the outside dimension of said piling to form an annular space therebetween, and stabilizing means alxed Yaround the exterior circumference of the bottom end of said sleeve to maintain said Sleeve in an upright position with portions of said sleeve above and below the level of the surface of said water surrounding said piling when said sleeve is placed in said water.

4. Means for protecting a piling from direct contact with ice forming on the surface of a body of water surrounding said piling-comprising in combination a tubular sleeve of buoyant plastic foam material having a predetermined inside dimension substantially larger than the outside dimension of said piling to form atubnlar" space therebetween, a weighted annular' stabilizing means affixed around the exteriorV circumference of the bottom end of said sleeve to maintain portions of Vsaid sleeve a-bove and `below the level of the surface of said water surrounding said piling and to maintain said sleeve in an upright position when placed in said water about, said piling, and an antifreeze solution of density less v than said water and insoluble therein filling theV space between said tubular sleeve and said piling.A

lS. An offshore well drilling platform comprising a main platform member, a plurality of piling members supporting said platform above the surface of a body of water, a drill rig positioned on said` platform, and means associated with each of said pilings for preventing ice forming on the surface of said water from attaching to said pilings; each of said last mentioned means including, a tubular sleeve of :buoyant plastic foam material having a predetermined inside dimension'larger than the outside dimension of a said piling to form a tubular space therebetween, a weighted annular stabilizing means Vaflixed around the exterior circumference of the bottom end of said sleeve to maintain said sleeve in an upright position when placed in said water about said pilings and an antifreeze solution of density less than said water and insoluble therein filling the space between said tubular sleeve and said associated piling.

6. The combination in accordance with claim 5 wherein said lantifreeze solution is oil.

References Cited UNITED STATES PATENTS 978,643 12/1910 Quist 6F54v 992,776 5/1911 Hubbard @1 54x 1,436,978 11/1922 Camp 61-54X 3,170,299 2/1965 Clarke 61,-1 3,180,099 4/1965 Mikoiaczyk er ai. 61-54 3,271,963 9/1966 menkam 61-46 FOREIGN PATENTS 721,34() 6/1942 Germany.

JACOB SHAPIRO, Primary Examiner.