Wharf fender

w. P. KINNEMAN

WHARF FENDER

Oct 13, 1953

Filed Oct. 21, 1952

2,655,005

Sheets-Sheet, 1

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2,655,005

Oct 13, 1953

W. P. K1NNEMAN

WHARF FENDER

Filed Oct. 21, 1952

Sheets-Sheet 2

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ATTORNEYS

Oct. 13, 1953 w. p. KiNNEMAN 2,655,005

WHARF FENDER

Filed Oct. 21, 1952 3 Sheets-Sheet 3

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ATTORNEYS.

Patented Oct. 13, 1953

2,655,005

UNITED STATES PATENT OFFICE

2,655,005

WHARF

William P. Kinneman, to Raymond Concrete N. Y., a corporation

Application October 21

Claims.

This invention relates to fender structures and arrangements, for wharves, piers and the like.

In the design of all structures used for mooring ships alongside, it has long been customary practice to use some method of protecting the ship from damage due to collisions between the ship and the structure. Such damage may occur both during the period of docking the ship and during the period when it is moored to the wharf bulkhead. While there is probably no practical means for insuring protection of the ship’s bow and the wharf structure from serious head-on collisions, yet it is important to provide some system of tendering which will eliminate so far as possible damages due to ordinary collisions and the usual buffeting caused by the surge and wind forces during the period while the ship is tied to the wharf. Present day ship schedules involving high speeds and very rapid “turn-arounds” are such that any delays due to even small injuries to the ships will involve heavy expenses. To minimize such injuries, wharf tendering sysr tems should perform three main functions. First, they must be capable of cushioning and quickly absorbing great amounts of energy, during several inches of movement when a ship collides with the fender at any angle, from straight on to broadside. Secondly, it is equally important that the tendering system be such as to widely distribute over a substantial portion of the wharf structure, the concentrated blows due to a ship striking at any angle. The third important function is to reduce abrasion damage between the wharf and the ship while the latter is moored.

In typical cases wharf tendering systems must be able to withstand the inertia of ships of 20,000 tons or more, moving at the rate, say, of one foot or more per second, and thus the structure must not only be capable of withstanding and distributing forces which are of a magnitude greater than and of a nature different from those met with by shock absorbing means for any other purposes, but at the same time the tendering system must be able to minimize the abrasive action and withstand longitudinal thrusts of the moored ship, due to tides, currents and, wind forces.

Aside from the common expedients of using mats, rope, old rubber tires and the like for the purpose, various attempts have, been made to solve, the problem by using steel springs, hydraulic shock absorbers, heavy weights and floating tanks, but such arrangements, unless made unduly complicated and expensive, are. incapable of satisfactorily .and permanently meeting all of

FENDER

Westfield, N. J., assignor Pile Company, New York, of New Jersey , 1952, Serial No. 315,944 (CI. 61—48) the above mentioned requirements of a satisfactory tendering system.

But by the present invention these requirements may all be fulfilled by providing a frame® work along the edge of the wharf in spaced relation thereto, and with cushioning means interposed at suitable intervals between such framework and the edge of the wharf, such cushioning means involving the use of rubber so arranged ¹⁰ and bonded to metal plates that the energy of the collisions will largely be absorbed and also distributed among adjacent cushioning units, by applying the forces to the rubber in a direction tending to subject the rubber to a shearing effect ⁵ and also preferably at the same time to some extent causing compression of the rubber.

It is now possible in various well known ways securely to. bond sheets or strips of rubber be. tween two metal plates applied to the surfaces ' thereof, and it is possible to utilize rubber sandwiched between metal plates in this way with the rubber working “in shear” with greater advantages than when the rubber is arranged to utilize _or its cushioning effect by subjecting it merely to direct compression. I have determined that for the purposes of providing cushioning means for wharf tendering systems, the use of rubber in shear is capable of providing a surprisingly satisfactory support for wharf tendering frameworks, 30 to withstand both the effects of collisions of the ship at various angles as well as the longitudinal forces of the ship when pressing against the tendering framework.

The framework preferably is faced with wooden 35 timbers and is supported by a series of piles.

Various further and more specific obiects, features and advantages of the invention will apnear from the following description, taken in connection with the accompanying drawings illus40 trating by way of examule the presently preferred embodiments of the invention.

In the drawings:

Fig. 1 is a plan view showing a preferred form of tendering arrangement constructed in accord45 ance with the invention;

Fig. 2 is· a nlan view on a larger scale showing further details of a preferred form of cushioning unit for the system of Fig. 1;

Fig.· 3 is a side view of one of the cushioning ⁵⁰ units and showing the manner in which same may be secured with respect to the edge of a wharf and to the tendering framework:

Fig. 4 is a face view of one of the rubber pad and metal plate assemblies used in forming the cushioning unit of Fig. 2;

2,668,005

Fig. 5 is a sectional view taken substantially along line 5—5 of Fig. 4;

Fig. 6 is a sectional view showing the manner in which assemblies such as of Fig. 5 may be secured to each other;

Fig. 7 is a perspective view of a wedge block embodied in the assembly of Fig. 2;

Fig. 8 is a horizontal sectional view of a modified form of cushioning unit;

Fig. 9 is a sectional view taken along line 9—9 of Fig. 8; and

Fig. 10 is a horizontal sectional view of another modified form of cushioning unit.

Referring now to Figs. 1-3 in further detail, an edge of a concrete wharf or dock is indicated at 11, a tendering framework formed of steel Ibeams or the like is indicated at 12 faced along its upper outer edge with wooden timber as at 13, the framework being supported as by a plurality of piles 15 so driven into the mud at the bottom of the body of water that the upper portions thereof and the framework carried thereby will be free to flex somewhat toward or away from the wharf face. A plurality of the abovementioned cushioning units are indicated at 16 interposed at spaced points along between the framework and the wharf.

A ship is indicated at 17 in Fig. 1 in a position about to be moored to the wharf. The steel sides of the ship while riding at its mooring will gradually cause abrasion of the timbers 13, but such abrasion will be substantially less than would be the case if the framework were not backed by the cushioning units, and in any event as the timber eventually becomes worn away, it may readily be replaced at comparatively small cost, as may also the wooden piles 15 if same become unduly worn. The steel framework 12 is preferably so constructed as to be fairly rigid when subjected to small forces and yet when subjected to forces involving the inertia of a heavy ship, the framework will yield to the extend permitted by the cushioning units 16.

Each of the cushioning units preferably comprises, as best shown in Fig. 2, a pair of spacedapart abutments as at 20, 21 formed by welding together steel plates to provide housing-like structures, such as shown, and which may be secured to the wharf as by anchor bolts 22. Each unit also includes a wedge block member as at 23 also formed by welding together steel plates to provide a structure in the form shown in Fig. 7 for example, and which is attached to the fender framework at 20 by bolts 25, preferably in the case of each unit, at a point opposite one of the piles 15. Also preferably as shown in Figs. 1 and 3, vertically positioned I-beams as at 26, 27 are so located as to be positioned between one of the piles and the point of attachment of the corresponding cushioning unit.

Between the wedge block member 23 and each of the abutments 20, 21, a series of cushioning elements is arranged, these being of a construction which will now be described in connection with Figs. 4 and 5. That is, as shown in section in Fig. 5, a layer of rubber as at 30 is interposed between and securely bonded to a pair of steel plates as at 31, 32 to provide a so-called “sandwich,” a face view of which appears in Fig. 4. The steel plates at their edges extend out beyond the rubber and are provided with bolt holes whereby pluralities of these sandwiches may be secured together in the manner shown in Fig. 6 by bolts as at 33, and similarly secured by bolts to flanges on the abutments 20, 21 and the wedge block 23 as indicated in Fig. 2.

As above indicated, the rubber may be securely bonded to the steel plates for example after brass plating the latter, in various ways which are well known and thus need not here be described, but which will assure such a firm bonding action that when such rubber sandwiches are subjected to powerful forces in shear, one of the steel plates will be yieldably movable generally parallel to the other without destroying the bond to the rubber, and thus providing a highly resilient cushioning means which will absorb great amounts of energy.

As shown in Fig. 2, the pluralities of these sandwich plates are bolted to the abutments and the wedge block in positions sloping slightly away from a vertical plane normal to the vertical surface of the wharf. This angle may vary for example from about 30% to about 45% depending upon the total required deflection and the desired maximum angle of distortion of the rubber. And the angle is such that when a ship collides with the framework head on, or at any fairly actute angle, the deflection of the rubber under the resulting load will be largely in shear, although to some extent also in compression. It will be appreciated that if the plates or sandwiches were all set normal to the wharf face, the rubber would be in pure shear and under some tension during its extreme deflection when a ship collides with the framework head on.

Thus in order to provide a desirable factor of safety against failure, the sandwich plates are preferably set at a small angle such that, even with a head on collision, the rubber is placed under some compression as well as in shear, and by so doing the possibility is avoided of ever placing the rubber under any such tension as might be destructive thereto during any normal operation of the tendering system. Furthermore, with the rubber sandwich means positioned as shown in Fig. 2, it will be apparent that the cushioning units will also be highly effective in resisting and cushioning longitudinal rubbing forces of heavy ships when moored parallel and under pressure against the wharf front. For these reasons the construction provides a substantial advantage over fender cushioning means heretofore proposed in the form of steel coil springs or volute springs, as well as a substantial advantage over other types of spring or resilient buffers which ivere only able effectively to resist or cushion the forces normal to the wharf.

In a typical case such as shown in Fig. 2, the steel framework is spaced about three feet from the edge of the wharf and the minimum distance between the faces of the two abutments 20, 21 is a little over four feet. The vertical dimension of the cushioning unit (as viewed in Fig. 3) of such example is about 18 inches. Each of the rubber sheets 30 is about three inches thick. Such a unit is calculated to permit inward cushioning movement of the steel framework through a distance of about one foot. It will be apparent that if a ship collides with the framework at any substantial angle to the normal, the component of the resulting force along the direction of the face of the wharf will cause one of the two series of sandwiches to be subjected to heavy compression while at the same time the component of force normal to the wharf face will largely be absorbed by placing the rubber in shear and by pushing the wedge block portion of the unit toward the wharf, with the result of wedging both

S of the 'series Of sandwiches Tespectively toward their abutments whereby neither of the two series ean'becoine subject to tension.

The total'deflection of the'cushioning units is determined by the thickness, number and offset angles of the rubber sandwiches, the durometer hardness of the rubber controlling the relation between the deflection and the load, preferably rubber having a durometer hardness of 60 is used, although the hardness may vary between 40 and 80.

With the rubber members shaped and positioned as shown in Figs. 2 and 6, substantially all of the rubber in the device is equally loaded and fully worked -when subjected to its maximum deflection. The unit is therefore efficient in the use of rubber, and since the maximum blows of a ship are infrequent and surging forces are small, the problem of heat dissipation is insignificant. Tire loading is temporary and will produce no permanent deformation- of the rubber.

-In case the wharf is one which is used for oil tankers, then neoprene or other suitable synthetic rubber or rubber-like materials may be used to avoid softening from oil spillage. Ih case the installation is near salt water, the metal plates if preferred are galvanized or coated with a rubber brushing compound to protect same from corrosion. The rubber itself will suffer no special deterioration in the presence of salt water. Where bright sunlight might cause surface deterioration of the rubber, the exposed surfaces thereof may be coated with any suitable known antioxidant compound. The cushioning units of the type above described have in addition to ease of maintenance and avoidance of excessive expense, several other advantage's as compared with spring or other types of mechanisms heretofore proposed for the purpose, in that relatively heavy and frictiohally engaging moving parts are avoided, thus avoiding wear and the necessity of lubrication. Also no close clearances are involved which would tend to be fouled by debris falling from the wharf or ships, and if failure should occur in any one of the rubber sandwiches, it can easily be replaced witliodt dismantling the entire device. Misalignment of the parts is impossible once the units are installed .and there are no guides or plungers to jam or bind.

The invention is adapted not only for use on the usual types Of wharves and piers, but also on ferry docks and bridges, bridge fenders, dolphins and the like, all of which are intended to be referred to by the term “wharf” as used in the appended claims.

While the cushioning units of the type shown in Fig. 2 are preferred as best meeting the requirements for wharf tendering purposes with the most economical use of the rubber and for convenient manufacture, alternative arrangements for utilizing rubber in shear for the purpose are shown in Figs. 8-10. For example in Fig. 8, annular rubber elements as at 40, 4i are shown as bonded interiorly to attached cylindrical elements as at 42, 43 and bonded externally to attached cylindrical elements 44 and 45, the inner cylindrical steel element being secured to tendering framework as at 48 and the outer cylindrical steel member being secured as shown to the edge of a dock 47. In this way two or more rubber members may be arranged in effect in tandem and iii a manner such that the rubber is placed in shear when ships collide head on, or at an acute angle with the tendering framework, the rubber also being subjected to compression, if the force b^rf the ship has ah important component longitudinally of the dock. From Fig. 8 it will be noted that the rubber is made thicker around the inner cylindrical members 42, '43 than at the peripheral portions. The thickness might of -course be made the same at the inner and outer portions of these annular rubber members, and then in that event the rubber adjacent the inner cylinders would be worked to a higher shear stress than at the outer cylinder'surfaces ahd hence the rubber would not be as efficiently used as when the rubber elements are shaped as shown in Fig. 8.

-In the embodiment shown in Fig. 10, annular rubber members as at 50, 51 and 52 are shown as bonded respectively in between cylindrical steel members 53—54, 55—53 and 57?-58; these cylindrical members being arranged in stepped relation as shown and so as to provide with the rubber elements sandwiched therebetween, an arrangement which in cross section is somewhat similar to that of Fig. 2, but being annular in form, it will be able to resist equally well not only longitudinal horizontally directed forces, but also forces parallel to the face of the dock either directed upwardly or downwardly, or at various angles to the vertical. It will be noted that the upper end surface of the rubber elements as shown in Fig. 10 -form truncated cones, for the same reason as above explained in connection with the rubber elements of Fig. 8. Also the lower surfaces of the rubber elements as shown in Fig. 10 are curved in cross-section in such a manner as to cause substantially uniform working of all of the rubber when subjected to shear. The construction of Fig. 10 may be mounted upon and secured to the dock and to the tendering framework in a manner which will be readily apparent from the drawing. It will also be apparent that with each of the embodiments shown, the broader portion of the cushioning unit may be mounted on the tendering framework instead of being mounted on the face of the dock, and the more pointed portion of the cushioning unit would then, of course, be secured to the dock.

Although -certain particular embodiments of the invention are herein disclosed for purposes of explanation, various further modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.