US2059025A

US2059025A - Tank car

Info

Publication number: US2059025A
Application number: US15299A
Authority: US
Inventors: Raymond C Pierce
Original assignee: GEN AMERICAN TANK CAR CORP
Current assignee: GEN AMERICAN TANK CAR CORP; GENERAL AMERICAN TANK CAR Corp
Priority date: 1935-04-08
Filing date: 1935-04-08
Publication date: 1936-10-27
Anticipated expiration: 1953-10-27

Description

R. C. PIERCE Oct. 27, 1936.

TANK CAR Filed April 8, 1935 l isili' mwm www@ m YIIIHHHHHHHUI llllll Il Patented Oct. 27, 1936 UNITED STATES PATENT FFQE TANK CAR Application April 8,

22 Claims.

My invention relates `more particularly, as

to one phase thereof, to anchors for tank cars;4

and as to another phase to the outlet legs thereof.

As regards the tank anchor feature, the invention relates particularly to an autogenous welded anchor, and as to the outlet leg feature to the novel coordinating of the leg with the 'anchor whereby it virtually becomes a part thereof.

Generally stated, my primary object is to so improve upon tank car structures that danger of failures at the anchors thereof will be reduced to the minimum.

In this connection it may be stated that tank cars in practice are subject to many different forces exerting different stresses at the anchored portion of the tank tending to impair the structure: in the case of wear of the bolster slabbing the tank becomes partly supported on the anchor resulting in shearing and bending stresses in the tank bottom; when cars are coupled together particularly when the slabbing for the tanks has worn and the tank bands are loose, there are strong vertical forces acting on the ends of the tanks, the tank tends to jump off the slabbing at one end which tends to reverse the stresses in the bottom of the tank shell at the anchor and results in tensile forces between the tank shell and the anchor: in addition to the above, twisting forces on the underframe are set up tending to twist the underframe in a horizontal direction with reference to the tank.

Thus the stresses on the anchor and the bottom of the tank shell at the anchor and which much be resisted thereby to render the structure most practicable, are most complicated and of great magnitude, the forces of the greatest magnitude being longitudinal forces due to buing, this condition having presented considerable olifculty particularly in the designing of cars having welded tank anchors especially as welding tends to change the structure of a metal to a considerable depth and introduces stresses be- 1935, Serial No. 15,299

Figure 1 is a broken plan view of a tank car the tank shell of which is anchored to the underframe in accordance with my invention.

Figure 2 is a view in side elevation of the structure shown in Fig. 1.

Figure 3 is a broken sectional view, the section being taken at the line 3 on Fig. 1 and viewed in the direction of the arrow.

Figure 4 is a fragmentary vertical sectional view, the section being taken at the line 4 on Fig. 1 and viewed in the direction of the arrow.

Figure 5 is a fragmentary perspective view of the tank shell and anchor, viewing the same from below; and

Figure 6, an enlarged broken view in cross` section through a tank shell and anchor constituting a modification of the construction shown in the preceding figures of the drawing.

Referring to the construction shown in Figs. 1-6, inclusive, "l represents the tank shell of a tank car and which may be of any desirable construction; and 8 represents the underirame of the car shown as of the center sill type comprising channel beams 9 spaced apart and extending lengthwise of the car as commonly provided in accordance with well known practice.

In the particular construction shown, the tank shell 'l is anchored substantially midway between `its ends to the underframe 8 leaving the ends of the tank shell to be supported on the underframe in any suitable manner, as for example in accordance with common practice, to permit of the longitudinal movement thereof in contracting and expanding, the ends of the tank shell commonly resting on bolster slabbing and held down by tank bands (not shown). Y

The anchor shown comprises a section lil of T-shape in cross section extending along the .underframe and the bottom of the tank shell li, the section i0 being formed of a pair of plates H of L-shape in cross section (which may be pressings) positioned back to back at their vertical flanges l2 with their substantially horizontal flanges i3 extending in opposite directions along the underside of the tank shell 'l to form a saddle therefor.

The plates ll when welded together at their ends and tack welded together along their bottom edges before application to the tank shell form the T-section l0 which may be provided at less expense than were it to be formed of one piece, the portions of the section Hl where the flanges i3 bend outwardly to form the tank saddle possessing a small amount of vertical flexibility which is quite desirable.

In accordance with my invention the tank shell 'I and the saddle-forming flanges I3 of the T-section III are corner or llet welded together but only along lines extending otherwise than lengthwise of the tank, preferably along lines substantially at right angles to the median line of the tank and thus substantially circumferentially of the tank, and the reasons, generally stated, for thus welding the tank to the anchor are as follows:

Welding against the surface of plates tends to change the grain structure of the metal and weaken the plates and while this tendency may be more or less corrected by subsequent annealing and heat treatment, danger of the metal being weakened at the weld always remains and it is therefore highly desirable that the welded structure be so provided that danger from weakened plates by welding will be eliminated or at least reduced to the minimum.

In the case of a cylindrical tank subjected t internal fluid pressure as in the case of tank cars the forces resulting from such pressure and tending to rupture longitudinal joints in the tank are twice as great as such forces tending to rupture circumferential joints in the tank.

Thus by conning the fillet welds between the tank and anchor to llet welds which extend only in a direction at an angle to the longitudinal axis of the tank, preferably at substantially a right angle thereto and thus eircumferentially of the tank, the weakening effect of the welds is minimized as such welds are subjected to only one-half of the force that they would be subjected to if the welds extended lengthwise of the tank.

Furthermore, while welds made in any direction against the surface of the tank will supposedly be of equal strength the A. S. M. E. and A. P. I, welding codes, in the calculation of resistance to bumng stresses, allow a credit for 25% greater strength in welds where the forces are at right angles to the line of the weld than where the forces are parallel with the welds. Thus by confining the fillet welds, attaching the anchors to the tank, in a circumferential direction only, not only is weakening of the tank in the direction of the greatest stresses to the internal pressure avoided, but a 25% increase in strength against buing forces is obtained, due to the fact that the anchorage forces which are lengthwise of the tank pass through the short angularly disposed welds.

The location of the welds as stated is effected in the construction shown by providing openings I4 in the anchor flanges I3, preferably closed at both ends and shown as elongated in a direction crosswise of the tank shell and welding these anchor flanges to the underside of the tank shell along those edges only of the openings I4 which extend crosswise of the tank shell, namely, the edges I as illustrated, and along the end edges It and I'I of the flanges I3, the openings I I of the series thereof in one of the flanges I3 being preferably staggered as shown relative to the openings I4 in the other flange I3.

At each end of each opening I4 are reliefs represented at I8 which serve as means for limiting the welds at the openings I4 to the desired length, namely, of a length equal to the length of the edges I5 whereby all of the welds extend crosswise of the tank shell, as the starting and stopping points for the welding are definitely delineated.

The anchor section I 0 is supported on the center sill 8 preferably by flexible connecting means shown as comprising a pair of plates I9 of similar form in cross section having horizontal portions 28 at which they are riveted, as indicated at 2|, to the sill-beams 9, vertical portions 22 between which the vertical flanges I2 of the section I0 are interposed and to which they are secured as by rivets 23, and intermediate downwardly bowed portions 24 affording to the plates I9 a certain amount of vertical and torsional ilexibility in a horizontal plane and at the same time effectively restraining longitudinal movement of the tank shell, permitting adjustment of the tank shell to worn slabbing and a certain amount of vertical action when the tank bands are loose.

Due to the Vertical forces acting on the anchor it is desirable to obtain a certain amount of flexibility between the outer edges of the anchor plates and the bottom of the tank shell. By

eliminating all welding within say about 1% inches to 2 inches of the lateral edges of the anchor flanges I3 and also by providing the reliefs I8 at the outer ends of the welds, which makes the anchor flanges weaker at the ends of the welds and therefore more flexible, a flexible construction is provided which prevents concentrated bending stresses on the tank shell.

Furthermore, in the particular construction shown the flanges I3 of the anchor are extended longitudinally beyond the vertical flanges I2, as represented at 25 thereby affording flexibility to the anchor between the outer extremities of the vertical flanges I2 and the welds along the edges I6 and I'I of the flanges I3.

The structure also comprises an outlet leg for the tank represented at 26 which is located in line with the vertical flange portion of the anchor section Ill, this flange section, together with the saddle forming llange portions thereof, being cut away to receive the leg which is rmly secured to the adjacent ends of the vertical portion of the anchor section III as by welding it thereto as represented at 21. The leg 26 is also preferably welded throughout its circumference to the wall of the o-pening in the saddle portion of the anchor through which it extends, as indicated at 28.

The construction shown in Fig. 6 is the same as that of the preceding figures except that the T-section of the anchor and herein represented at 29 (the tank shell being shown at 3D) instead of being formed of separate plate sections as in the case of the T-section I0, is formed as a onepiece structure and contains a single series of crosswise extending elongated openings one of which is shown at 3| and of the same form as the openings I4, with reliefs 32 at both ends of their long edges as explained of the openings I4, this single series of openings arranged to extend substantially equal distances beyond each side of the median line of the saddle being provided instead of the double row of openings I4. The anchor 29 would be connected with the tank shell 3l] by welding it only along those walls of the openings 3| which extend crosswise of the anchor between the relief portions 32 as explained above in connection with the construction shown in Figs. 1-4 and as illustrated at 33 of the one wall shown in Fig. 6.

While I have illustrated and described certain constructions constituting embodiments of my invention, I do not wish to be understood as intending to limit it thereto as the same may be variously modied and altered and the invention embodied in other forms of structure without departing from the spirit of my invention.

What I claim as new, and desire to secure by Letters Patent, is:

1. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded o-nly along lines disposed otherwise than longitudinally of the tank.

2. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded only along lines substantially circumferential of the tank.

3. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded at intervals along the tank only along lines disposed otherwise than longitudinally of theV tank.

4. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank towhich the tank is welded at intervals along the tank only along lines substantially circumferential of the tank.

5. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded at intervals along the tank and at its ends only along lines disposed otherwise than longitudinally of the tank.

6. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded at intervals along the tank and at its ends only along lines substantially circumferential of the tank.

7. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for Y the tank formed of a pair of L-shaped members to which the tank is Welded only along lines disposed otherwise than longitudinally of the tank. 8. In a tank car, the combination with its runderframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank formed of a pair of L-shaped members to each of which the tank is Welded at intervals along the tank only along lines disposed otherwise than longitudinally of the tank, the lines of weld at one of said members being staggered relative to the lines of weld at the other of said members. 9. In a tank car, the combination With its underframe, of a tank and means anchoring the tank to the underirame comprising a saddle for the tank formed as a one-piece structure and to which the tank is welded only along lines disposed otherwise than longitudinally of the tank. 10. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded, portions of said saddle extending outwardly beyond the welds and yieldingly resisting deflection of the tank. 1l. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is welded, the welds being inset from the longitudinal edges of the saddle wh-ereby these edges are free to yieldingly resist deflection of the tank. v

12. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank to which the tank is Welded along the ends of the saddle, and means supporting said saddle set back from the ends of the latter to permit the ends of the saddle to yieldingly resist deflectionof the tank.

13. In a tank car, the combination with its underframe, of a tank andv means anchoring the tank tothe underframecomprising a saddle for the tank to which the tank is welded only along lines disposed otherwise than longitudinally of the tank, portions of said saddle extending out- Wardly beyond the welds and yieldingly resisting deflection of the tank. Y

14. In a-tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank formed of a pair of L-shap'ed members positioned to form a T-member, and means engaging the vertical flanges of said members for connecting the latter with said underframe, said saddle being welded to said tank, portions of said saddle at its longitudinal edges extending beyond the welds whereby said portions are free to yieldingly resist deflection of the tank, said members having bends along the upper edges of said flanges and free to flex at said bends.

15. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank formed of a pair of L-shaped members positioned to form a T-member, and means engaging the vertical flanges of said members for connecting the latter with said underframe, said saddle being welded to said tank only along lines disposed otherwise than longitudinally of the tank, portions of said saddle at its longitudinal edges extending beyond the welds whereby said portions are free to yieldingly resist deflection of the tank, said members having bends along the upper edges of said flanges and free to flex at said bends.

16. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank containing elongated openings the long dimensions of which extend crosswise of the tank and welds connecting the saddle at the long edges of said openings to said tank.

17. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank containing elongated openings the long dimensions of which extend crosswise of the tank, said openings having reliefs at the ends of the walls thereof of longer dimension and welds connecting the saddle at the long edges of said opening to the tank.

18. In a tank car, the combination With its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank containing elongated openings reaching short of the longitudinal edges of the saddle, the long dimensions of said openings extending crosswise of the tank, said openings having reliefs at the ends of the walls thereof of longer dimension and welds connecting the saddle at the long edges of said openings to the tank, whereby the welds extend only crosswise of the tank and the longitudinal edge portions of the saddle are free to yieldingly resist deflection of the tank.

19. In a tank car, the combination with its underframe, of a tank and means anchoring the tank to the underframe comprising a saddle for the tank having endwise spaced apart web por- .tions, an outlet leg for the tank extending upsaddle portion containing openings presenting Walls extending crosswise of said member and at which the member is to be Welded to a tank, said portion having reliefs at the ends of said walls, for the purpose set forth.

22. In a tank car, the combination with its underframe, of a tank and means for anchoring the tank to the underframe comprising a saddle for the tank elongated lengthwise of the tank and to which the tank is Welded only along a longitudinal series of lines disposed crosswise of the tank.

RAYMOND C. PIERCE.