US2503210A - Water transportation of wood - Google Patents

Description

April 4, 1950 J. OHALLORAN WATER TRANSPORTATION 0F woqp Filed Feb. 10, 1947 April 4, 1950 J. OHALLORAN 2,

WATER TRANSPORTATION 0F wool? Filed Feb. 10, 1947 i-heets-sheet a April 4, 1950 v J. OHALLORAN WATER TRANSPORTATION 0F wow 4 Sheets-Sheet 4 Filed Feb. 10, 1947 Patented Apr. 4, 1950 WATER TRANSPORTATION OF WOOD James OHalloran, Quebec, Quebec, Canada, as-

signor to Anglo-Canadian Pulp and Paper Mills Limited, Quebec, Quebec, Canada, a corporation of Quebec Application February 10, 1947, Serial No. 727,643 In Canada December 17, 1946 1 Claim.

This invention relates to the ship transportation of floatable materials and more particularly to a method of loading and unIOading wood in conjunction with such ship transportation.

The transportation of pulpwood by ship is an operation which is in widespread use since in many instances it is the only feasible and economical manner of transporting wood despite its well-recognized disadvantages. The loading and unloading of ships with such material is timeconsuming and expensive, not to mention the hazardous working conditions under which the operations are carried out.

Under present practice, pulpwood is discharged into the ship hold from a chute leading from a ilume or other conveyor. After wood has been allowed to fiow down one of the present chutes into the hold until no more can be acked in by this method, the flow is stopped and another chute leading to another hold placed in operation. Men then walk on top of the loosely loaded wood in the loaded hold and level it on" approximately by throwing blocks of wood down into the voids which were left unfilled below the deck and into the corners of the hold under the chute. This is a hazardous and laborious operation as the wood is wet and slippery at the time.

When all holds of the boat have been looseloaded and levelled off by hand as described, the operation of putting on the deck load is started. To do this, wood is allowed to fall about the centre of a hatch opening and build up to a cone shaped pile about 8 feet high. This might represent about :cords of wood approximately. As soon as this pile has been made, another chute preferably as far away from the first one as possible is operated to form a similar pile. When wood stops dropping on the first pile, men immediately start cording, or ranking, the wood from the pile in two rows along the edge of the deck. As this process proceeds, a wall 8 feet thick and about 13 feet high is formed around the edge of the deck on the vessel. This leaves a space in the centre of the vessel about 27 feet wide by 150 feet long by 13 feet deep which can again be loose loaded with wood as in'the case of the holds of the vessel. The chutes are again operated consecutively as required to fill this space 'with wood. Care'must be taken durin this operation to insure that only sufficient wood is deposited at one time to enable the men to level it off flush with the corded wood around the edge of the deck. In spite of maximum care in this respect, there are several cords of wood lost over the side of the vessel. This has to be recovered later by a crew of men in a boat who operate a holding boom and reclaim the wood by eventually loading it into trucks and hauling it back to the starting point of the fiume.

Due to being unable to cord the wood up around the sides of the ship as rapidly as the capacity of the fiume, as well as the delay caused in levelling off the deck load on the vessel it is impossible to operate the flume at full capacity throughout the loading period which averages 10 hours. A boat which is loaded in 10 hours and carries an average load of 1000 cords, has therefore an average loading rate of only 100 cords per hour. Thus approximately one half the capacity of a normal flume which is rated at 200 cords per hour.

Moreover, a large crew is required to carry out this loading operation. Normally, about 30 men are employed and it requires about 10 hours for them to stow the 1000 cords capacity of the boat.

The unloading operation is likewise tedious and time-consuming. Usually, it requires a crew of men for about 2 hours to throw off the deck load, and a crew of 40 men for about 5 hours to unload the balance of the ship, in addition to the use of several cranes.

It is an object of the present invention to provide a method of loading and. unloading wood on and from ships which involves a very considerable saving of labor, as compared with the normal method described, and which is substantially free from hazardous working conditions.

Broadly, the invention contemplates the novel utilization of hydraulic power for stowing the wood during the loading operation and for discharging the wood during the unloading operation. It has heretofore been proposed to utilize air jets in the stowing of wood inv ships and to employ hydraulic power for the discharge of wood from ships, but such methods have not had practical commercial significance.

Briefly, the present method comprises the loading steps of admitting a quantity of water to a ships hold to provide a cushioning layer of water in the bottom of the hold, discharging a quantity of wood into the hold under water pressure to provide a layer of wood covering the bottom of the hold, pumping the cushioning layer of water out of the hold, discharging a further quantity of wood into th hold under water pressure, directing streams of water under pressure against the wood in the hold during at least a portion of the last-mentioned step to position the wood in the hold, and pumping the collected water out of the hold, and the unloading steps of directing streams of water under pressure against the wood at the top of the hold and adjacent one side thereof to discharge the same from the hold, admitting water into the hold at a ,point adjacent th opposite side of the hold to cause rising movement of the mass of wood in the hold, and cause a wood-carrying current to flow up into the space adjacent the first side of the hold from which wood has been discharged, while limiting the extent of rising movement of said mass of wood.

Other objects, details and advantages of the invention will become apparent 'as the description proceeds with particular reference to the accompanying drawings, in'which Figure l is a plan view of a ship and associated loading equipment,

Figure 2 is a transverse section of a ship during the loading operation,

Figure 3 i a diagrammatic plan view of the pipi-ngand pumping systems on the ship,

Figure 4 "is a transverse section of the ship and associated unloading equipment,

Figure 5 is a'plan View of the equipment illustrated in Figure 4,

Figure '6 is a partial longitudinal section of the shipand Figure 7 is an enlarged sectional elevation of the loading chute jets.

In the drawing, the ship 1 includes a plurality "of holds 2, having a main lower portion formed by substantial-1y vertical walls 3 and a minor restricted upper portion formed by converging or inwardly inclined flat wall section 4 surmounted by a shallow vertical wall portion 5 defining the hatch opening. A hatch coaming 6, of greater thenusualdepth, is preferably removably mounted on the portion 5. Each hatch coaming is proadded on either side adjacent the ship side with a generally trapezoidal shaped opening I having "a belt-mouthed entrance on its inner face to facilitate flow of wood therefrom. *Ea'ch opening is provided on its outer face with a watertigh-t door 8 hinged along its lower edge to the hatch c'o'aming.

The hatch walls or bulkhead-s 3 are preferably corrugated or ribbed vertically, as shown, in order to provide 'suificient strength with little loss of storage space.

The floor 9 of each hold is spaced from the ships bottom to provide a space In, and one, two or'more perforated or strainer sections I i are located inth'e viioor for communication with tanks 12.. Pipes I? connect each tank with a main pipe or pipes l4 which communicate with a header i6 inthe stern of the ship. A controlling valve 1G is provided in each pipe 13. The header 1% also communicates :at either end with strainers "I? at the :sides of the ship, valves l8 being provided to control such communication. :Pumps IE5 have their suction ports connected to the header and controlled "by valves [9. The discharge lines of the pumps lead overboard and are controlled by valves 2|. header between the main lines 1 4.

Between each pair of adjacent hatches and on the forward side of the forward hatch and the 'rearwa'rdside of the rear hatch are mounted a .pair of spaced .monitor nozzles 23 on platforms '24 elevated some distance above the hatch coamings. The platforms are preferably connected by a catwalk :25. Each nozzle is swivelly mounted so that its stream may be directed in varying directionas required.

A valve 22 is also provided in the plied under pressure through the pipe 41. pipe 41 maybe conveniently supplied with water The series of nozzles on each side of the ship are supplied with water under pressure by a pipe 26 connected to the discharge side of a pump 21. A main valve 28 controls the flow from each pump and a valve 29 controls the flow from each nozzle. The pumps 2'! have their suction side connected to the strainers ll, a valve 30 being installed between each pump and stainer in case of failure of either pump and the necessity of repairing it. Valve 3| is provided in a cross connection 32 between the lines 25 to permit either pump to be used for all the nozzles if necessary.

Referring to Figures 1 and 2, pulpwood to be loaded onto the ship is conveyed thereto by any usual'means as by the flume 33, in which case one or more transversely extending chutes 34 are mounted in fixed relation to the flume and spaced apart .a suflicient distance to discharge into different holds of the ship. A section of the flume is formed as a door 35, which when open acts to deflect the material in the fium'e into the chute. The walls of the chute adjacent the flume are curved, as indicated at 36, to provide ease of flow thereinto. The bottom of the chute is providedwith a grating 31 topermit discharge of the flume conveying water.

The chute 34 discharges into a segmental or flexible chute 38 comprising a plurality of overlapping sections 39 each connected to the adjacent section and to the grating chute '34 for -rel ative horizontal swinging movement about the pivot 39 and for relative vertical swinging movement about the hinge 0. Cables 4'! are connected to suitable power means to impart horizontal movement and cables 42 are connected to suitable power means to impart vertical movement.

Associated with the chute 34 are two or more water jets or nozzles 43 mounted at the outer end of the chute and adapted to direct the wood under water pressure through chute 3'8 and into the ships hold. Referring to Figure '7, the nozzles 43 are located at the end of the grating and in slightly spaced relation to the floor of the adjacent sec-tion of chute 38. The nozzles are supplied w-ith water from a header M which "communicates'by means of flexibl'e hose connections d5 witha secondheader flt, to which water is sup- The from the pumps 2-! on the ship, through a pipe connection 48 providedwi th a controlling valve 49.

Referring to Figures '4 and 5, which illustrate the unloading operation, there is provided a scow or pontoon 50 on which is mounted a large capacitylow head pumping plant 5 The scow is pre-ferably self-propelled by means of an outboard motor 52. The pumping plant comprises a plurality of pumps '53 of the axial flow type having submerged inlets 54 located in a well 55 at the base 'of the scow'prov'ided a grating =56. The pumps discharge into a header '51, provided with a flared outlet 58 adapted to direct the water vertically downward and to spread the flow .in a fore and aft direction. The outlet is adapted to discharge a comparatively large volume of water, i. e., from 30,000 te45,000 U. 3. gallons per minute.

slightly beyond the adjacent sides of the hatch openings, as shown in Figures -1 and 2. 'By suitably actuating the valves 6, I8, 19,21 and 22,

76 water may be permitted to flow by gravity from 7175 the strainers to theholdtobe loaded. The

"depth of'wateradmitted to; each hold prior to provide the cushioning? action be admitted, since, for effective stowing of wood in the hold,

this water must be subsequently removed. Ex-

perience has shown that the carrying of a large volume of water in the hold during loading has .adyerse effect on the efiiciency ofstowage. .Thus,

the; smaller the quantity of water which can be ;:usedfor cushioning purposes and the sooner this can besubsequently pumped out, the better 115111116. resulting stowage factor.

Following provision of the cushioning layer of water in a hold, the actual wood loading step is commenced. Pulpwood is supplied to the chute 34 either by water flume, as shown, or by mechanical conveyors or the like. As the wood slides down the lower end of the grating 31, and comes into contact with the high pressure jets 43, its movement is rapidly accelerated along the segmental chute 38 and projected therefrom into the hold. By controlling the volume and pressure of water issuing from the jets, the trajectory and volume of the wood issuing from the end of the chute may be closely controlled.

When a layer of Wood several feet thick, usually from 3 to 4 feet thick, has been deposited on the surface of the water in the hold, such water is pumped out of the hold leaving on the hold floor a layer of wood of sufficient thickness to serve as ample protection from impact of additional wood. Following placing of the cushioning layer of wood, the jets 43 are operated in conjunction with movement of the segmental chute to deposit about 50 per cent of the wood in the hold with good stowage efficiency. At this point usually, although it might be desirable before or after this stage, one Or alternatively two of the monitor nozzles 23 farthestaway from the discharge end of the chute are put into operation. The streams from these nozzles are directed at the Wood as it comes off the end of the chute and deflect it into the corners of the hold which are underneath the chute, as

another. By carrying on' with loading; of holds one after the other without: interruption in the mannerudescribed, a ship may be completely loaded ina much shorter time than that normally required for that. operation. Thus, it has been found that a vesselinay be loaded inthe manner described at the rate of 500 to 600 cords per'hour- Moreover, the loading operation described requires the employment of only two men,

namely, nozzle .operators, who do all the stowing of wood.

When loaded as described the ship corresponds "in all respects with a standard type of vessel in that all holds are .dry and other operating, and navigational features are normal. Travel of the .vessel between ports is therefore a normal procedure.

When the ship arrives at its destination port,

unloading thereof is proceeded with in amanner now: to be described. The self-propelled scow 50, which may receive its electric power supply from the power plant on the ship, comes along.- side the ship on the opposite side to that on which it is desired to discharge the wood, with the outlet 58 overhanging the hold to be unloaded. The watertight door covering the trapezoidal discharge opening on the opposite side of the hold is opened and lowered down towards the deck as shown in Figure 4. This door acts as a partial chute on which pulpwood can flow from the hold. The pumping plant on the scow is now actuated to discharge a wide stream of water vertically downward into the hold, and the two monitor nozzles farthest away from the opening are put into operation. It requires several minutes for the water supply from the scow to fill the hold and cause rising movement of the wood due to its buoyancy. During this time the high pressure streams of water from the monitor nozzles are knocking large quantities of wood shown in Figure 2. Following this stowage step, I

the nozzles 23 nearest the end of the chute are operated to deflect the Wood into the opposite corners of the hold. By using these nozzles 23 either singly or together, very efiicient stowage of wood can be eifected over the whole area of the hold. When the wood has been loaded into the hold to the top of the hatch coaming, it represents -a full load for that particular hold. Continuous pumping is carried on from a hold while the monitor nozzles and jets are in operation. This maintains the water level in the hold at zero so that the hold is comparatively dry when loading of it is completed.

Before loading is completed in a hold, a cushioning layer of water is admitted to another hold. Loading of the second hold can therefore commence immediately the preceding one has been filled. Gates on the fiume at each loading chute are so arranged that they can be opened or closed instantaneously as required for transference of the loading operation from one hold to out through the opening. In this manner, the level of pulpwood in front of the discharge opening is lowered to the same level as the bottom of the opening. This discharging of wood in front of the opening, by action of the impact of the streams of water only, is important in that it provides a pool of water in front of the opening when the mass of wood starts to rise. The large volume of water supplied by the scow flows down the inner face of the hold adjacent the scow, then along the bottom of the hold into the free space formed by rise of the mass of wood, and finally up the inner face of the hold under the discharge outlet. The water boils up into the pool created by the action of the nozzles and brings with it large quantities of wood which are discharged by the nozzles.

An important feature of the present invention resides in the fact that the mass of wood in the hold is restrained from rising more than a predetermined extent under the buoyancy of the water admitted to the hold by the scow. This restraint is imposed by the converging wall portions 4 and is necessary to prevent an indiscriminate outpouring of wood above the hatch in such quantity that handling thereof by the monitor nozzles would not be feasible. Thus, whereas With no restraint the mass in the hold might rise 15 feet, the bottleneck of the hold actually limits such rise to about 3 feet.

As soon as all of the pulpwood has been discharged from a hold in the -manner described, the scow moves to the next hold which it is desired to unload. At the same instant, the pumps on board ship are put into operation for dewatering the hold. from which the wood has just been discharged; The time for dewatering a holdv is slightly less thanthe time required to discharge wood from a hold. so that dewatering is completed before the scow again moves to another hold. By unloading the holds in sequence in this. manner, an. overall rate of unloading can be reached which is many times more rapid than. usual methods.

Thus, it has been found that pulpwood can be discharged up to rates as high as 800 cords per hour per hold. Only two nozzle operators and a crew: of three on the scow are required. At no time is there more than two holds either partially or wholly full of water. There are a suflicient number of holds in the ship that the stability of the vessel is never endangered when operating as described.

I claim:

A method of loading pulpwood onto a ship which comprises admitting a cushioning layer of water to cover the bottom of a hold of the ship, discharging a quantity of wood into the hold to REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,370,912 Reid Mar. 8, 1921 1,405,173 Wheeler Jan. 31, 1922 1,528,549 Hoyt Mar. 3, 1925 1,676,757 West July 10, 1928 1,837,165 Lewis Dec. 15, 1931

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