USRE21359E

USRE21359E - Ship construction

Info

Publication number: USRE21359E
Authority: US
Publication date: 1940-02-20

Description

Feb. 20, 1940. H. P. FREAR SHIP CONSTRUCTION Original Filed July 19, 1934 4 Sheets-Sheet 1 M H We Feb. 20, 1940. H. P. FREAR SHIP CONSTRUCTION Original Filed July 19, 1934 4 Sheets-Sheet 2 Feb. 20, 1940. H; P. FREAR SHIP CONSTRUCTION Original Filed July 19, 1934 Feb. 20, 1910. H. P. FREAR sxm coNs'rnUcTIoN 4 Sheets-Sheet 4 Original Filed July 19, 1934 Qwuentoz Reiesued Feb. 20. 1940 UNITED STATES PATENT OFFICE SHIP CONSTRUCTION Hugo P. Frear, New York, N. Y., assignor, by

mesne assignments, to Bethlehem Steel Company, a corporation of Pennsylvania Claims.

This invention relates to improvements in the structure of floating vessels or ships of all types, but especially to vessels designed to carry liquid cargo in bulk, commonly called tankers, and built 5 on the quasi longitudinal system of framing.

The present application is a re-issue application of my Patent No. 2,103,715, Serial No. 59,211, filed January 15, 1936, which was a continuationin-part of my then co-pending application, Serial No. 688,574, flied September 8, 1933, which issued as Patent No. 2,053,903, and was a divisional application of my then co-pending application, Serial No. 735,923, filed July 19, 1934, which issued as Patent No. 2,053,904. In another appli- 5 cation (Serial No. 59,212, Patent No. 2,071,925)

filed concurrently with my application, Serial No. 59,211, I have disclosed and claimed broadly the feature of maintaining continuity of strength of iongitudinals where out by the bulkheads and this present application discloses and claims a specific form thereof.

The chief object of the present invention is to provide improved means for maintaining continuity of strength in the longitudinals of the ship's framing where cut by the bulkheads.

Another object of the present invention is to provide continuity of strength in the longitudinals of the ship's framing where cut by the bulkheads by welding additional metal to connect the ends of the longitudinals where cut by the bulkheads and to have this additional metal of a preferred shape as will hereinafter be described and set forth.

Another object of the present invention is to 5 reduce to normal the unit stresses developed in theships plating at'the line of the transverse bulkheads.

Another object of the present invention is to make a considerable saving in the weight 01' 40 the framing of the ship over the usual framing with its initial saving in cost and future savings due to added capacity and reduced tolls.

With these objects in view, the present invention, broadly stated, resides in a ship or the like, particularly for carrying liquid cargo in bulk, in which longitudinal stiifeners are cut at a transverse bulkhead, and in which strength is restored to the stifieners across the bulkhead at the outer portions of the stiifeners by plates having edges welded to the stifieners and other edges welded to the bulkhead or to boundary bars associated therewith and at the inner portions of said stifleners by a round bar extending watertight through the bulkhead by reason of being welded thereto and welded to the ends of the stifleners.

By using a round bar at this point I have found that itcombines with a high eiliciency inincreasing the section modulus a particular adapta- 5 bility to its being welded to the longitudinals, by reason of the angles, formed when in contact with the longitudinals which angles are ideal for receiving the weld metal, and by reason of its convenient approach for welding. Furthermore 10 the round section requires only the simplest form of piercing of the bulkhead platingthat of a round hole which may be formed either by means of the welding torch, or arc; or by the more conventional means of drilling or punching.

The novel features will be more fully understood from the following description and claims taken with the drawings, in which:

Fig. 1 is a partial section through a vessel lllustrating one form of continuing the strength 20 of longitudinals through the bulkheads;

Fig. 2 is a cross-section taken along the line 2-2 of Fig. 1;

Fig. 3 is a cross-section taken along the line 3-3 of Fig. 1;

Fig. 4 is a similar view to Fig. 1 illustrating a modification in the bulkhead;

Fig. 5 is a cross-section taken along theline 55 of Fig. '7;

Fig. 6 is a cross-section taken along the line 30 6-6 of Fig. 5;

Fig. 7 is a view taken on the line ll of Fig. 5;

Fig. 8 is a cross-section taken along the line 88 of Fig. 10 illustrating a further modlflcation;

Fig. 9 is a cross-section taken along the line 9-9 of Fig. 8;

Fig. 10 is a view taken on the line Ill-l0 of Fi 8:

Fig. 11 is a diagrammatic layout of a hold plan of a vessel with transverse and longitudinal bulkheads adapted for longitudinal framing embodying my invention;

Fig. 12 is an enlarged cross-section in part taken on the line l2l2 of Fig. 11 and illustrates the longitudinal framing;

Fig. 13 is a longitudinal section taken horizontally through a portion of the vessel of Fig. 11 and illustrates the embodiment of my invention to the ship's longitudinals; and

Fig. 14 is a modification of Fig. 4 and embodies my invention in its simplest form.

Referring now to Figures 1, 2, 3, 11, 12, and 13, the bulkhead plating III is shown suitably attached to the bulkhead boundary bar H a by welding H. The longitudinal stifl'eners ll have their outer or plating flanges strengthened and extended in breadth on both sides and toward the ends by means of the flange extension plates l4 welded as at IE to the stifl'eners it. As assembled in the finished vessel the extension plates l4 together with the cut ends of the stifl'eners I3 are welded as at It to the plating flanges ll of the boundary bar H. Member I8 is preferably a round tie rod passing through the bulkhead plating I0 and welded or fused to the adjacent ends of the aligned longitudinal stifleners l3. It is also welded watertight to the bulkhead plating II) as at l9.

In Fig. 4 I show a modification to the design shown in Figs. 1, 2, and 3. In this modification the boundary bar comprises two angle bars 2| suitably attached to the bulkhead plating and has the heels of the bars 2| welded together as at 22, and the horizontal flanges of the bars 2| welded, as at 23, to the flanges of the stifieners l3 in a manner similar to that shown in Figs. 1 and 2.

In case it is necessary to provide for drainage through the stifleners, I may do so by means ofthe slots 24 in Figs. 1 and 2. The edges of the slots are securely welded to the ships plating.

The stiifeners l3 are preferably continuously welded to the ship's plating as at 25.

The extension plates l4 may be increased or reduced or be limited to one side only of the stifieners l3 as the exigencies of interference of plate or other circumstances in design demand.

By reason of the flange extension plates [4 being welded to the stifieners l3, and both in turn welded to the boundary bar II, the continuity of strength at the outer flange of the stifieners I3 is maintained; and by reason of the tie rod l8 welded or fused to the inner flanges of the stiffeners |3 the continuity of strength at the inner flange is maintained. Furthermore by proper proportioning of the extension plates I4 and the tie rod l8 the continuity of strength in the stiffener through the bulkhead both longitudinally and as a beam may be maintained. The pull of the aligned stifieners I3 is carried through the bulkhead without cutting the boundary bar H or the passing of doublings under the bar, thereby avoiding the objection of increasing the number of plies for riveting and the difliculty of making and keeping tight. The flanges ll of the boundary bar II is neutral as far as performing any longitudinal work on the plating goes, so that the eflect of joining the aligned longitudinal stifieners l3, as described, is to restore the plating to exactly the same condition it would have been in if the stiflfeners had not been cut. Furthermore, as broadly disclosed and claimed in my application (Serial No. 59,212, Patent No. 2,071,925) filed concurrently with my application (Serial No. 59,211, Patent No. 2,103,715), the latter being the original application of the present re-issue application, by the proper proportioning of the extension plates l4 and the tie rod I8 I am able to make a considerable saving in weight of longitudinals over prior practice. I make this saving, as described in said application, by so proportioning the extension plates I4 and the tie rod it that the section modulus thereof adjacent the bulkhead plating shall not be less than the sectional modulus of the stiffeners l3 in way of the web members 25. The sectional area of the tie rod l8 and the area of the plating between two adjacent stiflener ends is solely used in calculating the sectional modulus. The length of tie rod It on either side of the bulkheads along the stifleners l3, as disclosed in the aforesaid application, is such that it is not short of the point nearest the bulkhead in the stiifeners l3 where the bending moment'of said stiifeners is not less than the bending moment midway between the bulkheads and the nearest web member, or for a distance preferably not beyond the point of inflection nearest the bulkhead. The said two points being respectively approximately 10% and 21% of the distance from the bulkhead to the nearest web member. When thus properly calculated I am enabled to make my stiffeners l3 of the minimum section as determined by the stresses midway be tween the supports instead of, as has been the practice heretofore, having the section determined by the stresses at the supports. The saving in weight is readily seen to be an important feature of my invention.

In Figs. 5, 6, and 7 I show a modification to the design shown in Figs. 1, 2,'and 3. In this modification the longitudinal stifleners 21 comprise a. web plate 28 continuously welded as at 29 along its outer edge to the ships plating 30 and having welded along its inner edge the reenforcing bar 3|. At the ends of stifleners 21 where cut by the bulkheads 32 (similar to II! of Fig. 1) the outer edge of the web plate 28 is coped out to accommodate the flange plate or bracket 33. The cope in the web plate 28 is allowed to extend beyond the end of the flange plate 33 to provide a drain opening 34. The flange plate 33 is welded to the web plate 28 as at 35 and is welded to the ship's plating 3B and to the bulkhead 32 as shown at 36 and 31 respectively.

In Figs. 8, 9, and 10 I show another modification to the design shown in Figs. 1, 2, and 3. The bulkhead 3B and the boundary bar 39 may be similar to that shown in Fig. 1. The longitudinal stiflfeners 4|! comprise an angle bulb beam. The stiffeners 40 are coped at the ends to accommodate the flange plates 4| in a similar manner as that just described for the stiiIeners 21.

In still another modification, shown in Fig. 14, it is obvious that one or both of the boundary bars 2| of Fig. 4 could be dispensed with and in such cases the longitudinal stiifeners 42 would be welded directly to the bulkhead 43 by the weld metal 44.

In Fig. 11 I have shown diagrammatically a hold plan of a type of vessel particularly adapted for embodying my invention. The vessel would be constructed with plating on the bottom 45,

- sides 46, and deck 41, on the quasi longitudinal system of framing, especially designed to carry a liquid cargo in bulk. It would comprise a. plurality of tanks 48 formed by longitudinal bulkheads 49 and closely spaced transverse bulkheads 50 attached to the ship's plating 46 and to the longitudinal bulkheads 49. The transverse bulkheads 5|! would comprise the plating HI and the boundary bars ll of Fig. 1. Referring now to Figs. 12 and 13, the framing of the vessel would comprise relatively deep and widely spaced transverse webs 26 attached to the ships plating and to the longitudinal bulkheads. The framing would also comprise relatively narrow and closely spaced longitudinal stlffeners 5|. The said stiffeners 5| would comprise the members I3 of Fig. 1 or its hereinbefore described modification.

The terms and expressions which I have herein employed are used as terms of description and not or limitation, and I have no intention, in the use of such terms and expressions, of excluding any equivalents of the features thereof, but recognize that various modifications are possible within the scope oi the invention claimed.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a vessel of quasi longitudinal construction, transverse bulkheads, fore-and-ai't walls, water-tight means attaching the peripheral edges of said bulkheads to said walls, longitudinal stitfeners comprising inner and outer flanges cut through by said bulkheads in such a manner that the cut ends are in proximity to but in spaced relation to said bulkheads on each side thereof, said outer flanges being attached to their adlacent one of said walls and at said out ends beingwelded to their adjacent one of said means, and round tie rods piercing said bulkheads and welded water-tight and completely around its periphery to said bulkheads and welded to said inner flanges of adjacent cut ends of said stiii'eners.

2. In a vessel of quasi longitudinal construction, transverse bulkheads, fore-and-aft walls, water-tight means attaching the peripheral edges of said bulkheads to said walls, longitudinal stilfeners comprising inner and outer flanges cut through by said bulkheads in such a manner that the cut ends are in proximity to but in spaced relation to said bulkheads on each side thereof, and round tie rods piercing said bulkheads and welded water-tight and completely around its periphery to said bulkheads and welded to said inner flanges oi adjacent cut ends of said stiteners.

3. In a vessel, a plate member, a stiiiener comprising an inner chord member cut throu h by said plate member in such a manner that the cut inner chord member is in proximity to but in spaced relation to said plate member on each side thereof, and a round tie rod piercing said plate member and welded water-tight to said plate member and welded to the cut ends of said inner chord member.

4. In a vessel, a plate member, a stifl'ener comprising inner and outer chord members out through by said bulkhead in such a manner that the cut inner chord member is in proximity to but in spaced relation to said plate member on each side thereof, and a round tie rod piercing said plate member and welded water-tight to said plate member and welded to said inner chord members of the cut ends oi said stiflener.

5. In a vessel, a bulkhead, fore and aft walls, water-tight means attaching the peripheral edges of said bulkhead to said walls, a stiffener comprising inner and outer chord portions cut through by said bulkhead in such manner that the cut ends of said chords are in proximity to but in spaced relation to said bulkhead on each side thereof, said out outer chord portions being attached to their adjacent one of said walls and at said out ends being welded to their adjacent one of said means, and a round tie rod piercing sai'd bulkhead and welded water-tight around its periphery to said bulkhead and welded to said inner chord portions of the cut ends 01' said stiti'ener.