[0001] The object of the present invention is a railway tank car with a frame mounted on
two two-axle trucks, where the railway tank, cistern, is mounted in saddles.
[0002] American patent specification US 4284012 describes a railway tank car, where the tank is mounted on two saddles that are placed
on an underframe and two-axle trucks, while those trucks are independent units. The
saddles are shaped as extended boxes, closed from both sides with membranes, from
the other two sides - with support metal plates, and with a bow-shaped strip from
the top, the radius of which is matching the outside diameter of the tank. The entire
box is stiffened by ribs inside the saddle. The bottom surface of the saddle is formed
by a number of plates arranged on different levels and fitting the shape of the upper
surface of the frame. A vertical symmetry axis of each saddle virtually corresponds
to the vertical symmetry axis of a particular truck. Also in the railway tank car
according to the
German patent specification DE 1605105 C3 the tank is placed on two saddles fixed to crosswise frame members, and the frame
consists of two crosspieces in the area of riding trucks, connected to two parallel
longitudinal shaped members. The tank is locked in a saddle by screw fasteners fixed
in a tank guide and the upper edges of saddle supporting plates. According to both
solutions, the saddle breadth at its base definitely exceeds the largest dimension
of the part in contact with the external surface of the tank, which is a chord of
the saddle upper strip.
[0003] Construction of a tank mounting in a tank car, as known from a specification in the
Polish patent application P-301894 (published in the Biuletyn Urzedu Patentowego (Patent Office Bulletin) No. 18/1997),
includes two saddles resting on turning beams of a chassis. Each saddle is composed
of two membranes, two support metal plates secured on the outside to the membranes
and to the chassis. The tank rests on strips with a radial pad on top, and the strips
are welded to the support plates. Strips are pre-shaped in form of a bow with the
radius equal to a sum of the outside tank radius plus pad thickness. Saddle membranes
are shaped accordingly as well. Stiffening ribs are welded to the strip and membranes.
In the lower part of the tank jacket, on its both sides, welded are lugs profiled
of a welded T-bar, provided with holes for screw connections with guides running along
considerable part of cylindrical section of the tank and welded to the strip in the
saddle area. Lugs, guides and screw fittings allow to make solid joint between the
tank and saddles, and through that to the chassis.
[0004] Similar way of tank mounting in a railway tank car is known from a specification
of a claimed Polish utility model Ru
57822. Here the tank rests on two supports - saddles located above king pins in moving
trucks. Two rhomboidal side retaining plates of each support are permanently secured
vertically to a frame over the running truck. Vertical symmetry axes of the rhomboidal
side retaining plates go near to vertical symmetry axes of trucks. The side retaining
plates are bent at the top to form strips, and the upper edges of the strips ascend
askew towards the tank. A tee bar is welded to the tank jacket on each side of the
tank, alongside its entire cylindrical section, the tee bar flange being in contact
with the tank surface, while its central part is situated above the side retaining
plate of the support. Tee bars and strips on both sides of the tank are connected
to each other by screws.
[0005] An underframe for railway tank cars as known from a specification of a claimed Polish
utility model Ru
60303 includes a railway tank saddle which is inseparably attached to the car chassis.
The saddle consists of four saddle webs and two lengthwise saddle plates. The saddle
lengthwise plates are attached to side sills of the chassis. Saddle webs are attached
to the car chassis turning beams, and are tied in pairs by pads made of a tee bar.
The saddle webs are also attached perpendicularly to the saddle lengthwise plates,
and those are inseparably attached to the car tank along its generating line. Pads
made of a tee bar, tie the saddle webs in pairs, and are so design-positioned as their
tee-bar flanges are facing the external surface of the tank jacket, and together with
spacers, those flanges form a tank support in the area situated over the car chassis
turning beams. The pad web is flush with the saddle webs and welded to them once the
entire pad together with the spacer have been pushed close to the tank jacket. Saddle
pads are not attached to the railway tank. The tank rests on them by gravity. Mounting
technology must provide close adherence of pads to the tank, without visible gaps
between the tank jacket and pads, and between spacers and tee-bar pads.
[0006] A railway tank car, where the railway tank is seated on saddles of U-shaped cross-section,
and the saddles consist of a base and side walls and rest on a car frame; and where
pads are provided on the railway tank; such a railway tank car according to the invention
is distinguished by that the upper edge of the saddle side wall is attached to the
pad of the railway tank, and that there is a gap between the saddle base and the frame.
The upper edge of the saddle side wall is welded to the pad of the railway tank. The
gap between the saddle base and the frame is closed by a spacer made of any material
of one's choice. Except that the spacer is flexible, made of plastic, preferably of
polypropylene. Length of the saddle base is substantially smaller than the maximum
dimension which is the chord formed by the upper edge of the saddle side wall. Whereas
the spacer is similar in shape to the rectangular base of the saddle. There are profiled
lugs at both ends of the railway tank on its both sides, welded at the bottom to a
turning beam of the frame and, at the top, to a strip of the railway tank. One of
side walls and a saddle base are formed of rolled angle, and the other side wall of
a saddle is formed of sheet metal; and those parts are joined by a weld at the saddle
base. An axis of symmetry of each saddle is shifted towards the centre of the railway
tank car, in relation to the vertical axis of the two-axle truck of the railway tank
car.
[0007] Construction of a railway tank car according to the invention is characterised in
the first place by simplicity of fabrication of individual components designed to
attach the tank. This solution makes the job of tank mounting on a car chassis, and
thus the set-up of the entire tank car, definitely easier and less time-consuming
as compared to other constructions, wherein in order to mount a tank, support elements
are pressed against the tank surface using special design and engineering procedures
aimed at attaining a correct saddle-tank fit, i.e. without any gaps between supports
and the tank.
[0008] A major advantage resulting from the construction of the railway tank car according
to the invention consists in shorter mounting time, due to the fact that the tank
saddle is permanently attached to the car tank by welding, thus gaps between the tank
and support can be eliminated. The saddle is joined to the turning beam by gravitation,
through a plastic spacer, and the contact surface is clearly smaller than in the case
of the saddle-tank contact surface, therefore a correct fit on a turning beam without
excessive gaps can be easier achieved.
[0009] In respect of the design and strength, the solution according to the invention is
characteristic of more gentle and smooth introducing static and dynamic forces as
well as the stresses resulting thereof into the tank. The reasons of that fact are
as follows. Each butt joint by gravity between a saddle and a tank involves errors
within tolerance limits, in shape of adjoining surfaces. When such joint is used,
as according to the invention - between a saddle and turning beam, and not between
a saddle and a tank, as in previous constructions, the tank jacket will be free of
additional stresses resulting from the tank-chassis matching error.
[0010] The object of the invention is presented in figures below in an exemplary model,
where Fig. 1 presents is a side view of the tank with the railway tank car elements
marked schematically, and with broken-out sections of the profiled bracket showing
a view of the saddle; Fig. 2 shows a partial cross-section of the railway tank car
in the saddle area, along A-A line from Fig. 1, in a larger scale; Fig.3 shows a partial
cross-section of the railway tank car in the area in front of the saddle, along B-B
line from Fig. 1, in a larger scale; Fig. 4 - a side view of the saddle alone; Fig.
5 - a cross-section of the saddle made of three welded pieces, along C-C line from
Fig.4, in a larger scale; and Fig. 6 - a cross-section of the saddle made of two pieces,
in a larger scale.
[0011] The basic element of the railway tank car according to the invention is a tank
- a railway tank 1. The railway tank 1 rests on two saddles 2, where each saddle 2 is welded to it through a pad 3, and the pad 3, shaped in accordance with the diameter of the railway tank 1, is welded directly to a jacket 4 of the railway tank 1. The saddles 2 rest on a frame 5 of the railway tank car. The frame 5 is placed on two two-axle trucks 6. The basic elements of the frame 5 are two turning beams 7 and an edge beam 8 that joins the two turning beams 7. Each saddle 2 is seated on the turning beam 7 of the frame 5, and it is placed in such a way that the axis of symmetry 9 of the saddle 2 is shifted towards the centre of the railway tank car, in relation to the vertical
axis 10 of the two-axle truck 6.
[0012] The saddle
2 of a cross-section shaped as a capital letter U consists of two side walls
11 and a horizontal base
12. Each side wall
11 ends at the top with an upper edge
13 shaped after the radius and exactly matching the outside diameter of the pad
3 which is welded to the jacket
4 of the railway tank
1. The saddle
2 is permanently attached to the railway tank
1 by welds run between the upper edge
13 of each side wall
11 and the pad
3. Length of the base
12 is substantially smaller than the maximum dimension which is the chord of the arch
formed by the upper edge
13 of the side wall
11. Stiffness of the saddle
2 has been achieved by welding ribs
14 inside the saddle
2 near the ends of the base
12. The entire saddle, its two side walls
11 and the base
12 can be made of sheet metal by marking-off and cutting out the whole thing in shape
of a capital letter "U".
[0013] Individual elements of the saddle
2, i.e. two side walls
11 and the base
12, can be made also on separate work stands, as marked-off and then cut out elements
of sheet metal. Next, the so prepared elements are joined together by welding, placing
two welds
15 at the base
12. Considerable stiffness of the saddle
2 has been achieved by using rolled angle
16 and sheet metal
17 to make such element. Unsymmetrical rolled angle
16, for ex ample a section 200 x 100 x 12 mm, can be used to make one element of the
saddle
2, that forms at the same time also one of side walls
11 and a horizontal base
12. Whereas the second side wall
11 of the saddle
2 is made of sheet metal
17. The rolled angle
16 and the sheet metal
17 to be joined together by only one weld, laid near the base
12. Of course, there are also ribs
14 inside both saddles
2 that have been made as described above.
[0014] Each saddle
2 is welded on the railway tank
1 and rests free on the turning beam
7 of the frame
5, and there is a flexible rectangular spacer
18 placed loosely between the base
12 surface of the saddle
2 and the top surface of the turning beam
7. Such solution results in that the saddle
2 of the railway tank
1 is not attached to the railway tank car frame
5 in any permanent way. Since the saddle
2 rests on a flexible rectangular spacer
18, the railway tank
1 can move free within the thermal expansion limits, depending on the type of transported
foods. Preferably the spacer
18 to be made of plastic, e.g. polypropylene.
[0015] There are strips
19 welded to the jacket
4 of the railway tank
1 on its both sides, close above the upper edge of the pads
3. Each strip
19 runs over the entire length of the cylindrical section
20 of the railway tank
1, and overlaps its both heads
21. The strip
19 terminates at both ends in an oval piece
22 welded to the head
21. Side plates in form of profiled lugs
23 are provided on both sides of the railway tank
1, in the area of both two-axle trucks
6. The profiled lugs
23 permanently join the railway tank
1 with the frame
5 of the railway tank car. Actually the lower edge of the profiled lug
23 is welded on the external U-iron
24 of the turning beam
7 of the frame
5. Whereas the upper edge of the profiled lug
23 is welded on the strip
19, near the end of the cylindrical section
20 and near the head
21 as well, and through the strip
19 it joins to the railway tank
1. The profiled lugs
23 serve to position the railway tank
1 in the axial center line of the railway tank car, thus transmitting the lengthwise
forces and shearing forces. While the saddle
2, since it is welded on the railway tank
1, transmits vertical-acting forces induced by the load and own weight of the tank.
[0016] Mounting the saddle
2 and placing the railway tank
1 on the frame
5 of the railway tank car designed according to the invention, proceeds in the following
way. Two saddles 2 have to be made in the first place, and then, as a complete subassembly,
are welded on the railway tank
1. The two saddles
2 are made of three pieces forming the base
12 and two side walls
11. The saddles
2 can also be made of two pieces, using rolled angle
16 and sheet metal
17. Also ribs
14 are welded on inside each saddle
2. Two pads
3 are welded from underneath on the jacket
4 of the railway tank
1 composed of the cylindrical section
20 and two heads
21, in the terminal area of the cylindrical section
20. Close above the upper edge of the pads
3, also strips
19 are welded on the jacket
4. on both sides of the railway tank
1, and those strips
19 have to be welded on both, the cylindrical section
20 and the heads
21 as well. Once the railway tank
1 has been welded as provided above, both saddles
2 are applied to it, the saddles
2 well matching the pads
3, since dimensions of the upper edges
13 of the side walls
11 in the saddles
2 closely correspond to the outside diameter of the pad
3. While attaching the saddles
2 to pads
3, one should remember of suitable positioning the saddles
2. Having placed the railway tank
1 on the frame
5, such relation should be obtained that the symmetry axis
9 of the saddle
2 is shifted towards the centre of the railway tank car in comparison with the vertical
axis
10 of the two-axle truck
6. So positioned both saddles
2 are welded then directly on pads
3. All gaps, unevenness, which may appear between the upper edge
13 of side walls
11 in the saddles
2 and the external surface of the pad
3 will disappear as a result of welding process performed on those parts.
[0017] Next, the railway tank
1 with the saddles
2 welded on, is to be placed on the frame
5 of the railway tank car, and then the profiled lugs
23 are to be welded on, by which the railway tank
1 will become permanently attached to the frame
5 of the railway tank car. Immediately before the railway tank
1 with the saddles
2 welded on is to be put down, rectangular plastic spacers
18 slightly larger than the rectangular base
12 of the saddle
2 are to be placed on both turning beams
7 of the frame
5. The pin
25 that is fixed to the turning beam
7, will prevent the spacer
18 from sliding when the railway tank car runs unloaded. So then the railway tank
1 with the saddles
2 welded on, is placed on the frame
5 of the railway tank car, directly on spacers
18 that have been already lying on the turning beams
7 of the frame
5. The railway tank
1, having been set-up as indicated above, is to be fastened together with the frame
5 through the profiled lugs
23. Having checked the accuracy of the railway tank positioning on both two-axle trucks
6, the welds are made between the lower edge of the profiled lug
23 and the external U-iron
24 of the turning beam
7 of the frame
5, as well as between the upper edge of the profiled lug
23, the strip 19 and the oval piece 22, where both the said strip 19 and the oval piece
22 have been welded on the cylindrical section
20 and also on the head
21. Set-up of the railway tank car as described above is simple and easy to carry out.
1. A railway tank car, where a railway tank is seated on saddles of U-shaped cross-section,
and the saddles consist of a base and side walls and rest on a car frame, and where
pads are provided on the railway tank, characterised in that the upper edge (13) of the side wall (11) in the saddle (2) is attached to the pad
(3) of the railway tank (1), and that there is a gap between the base (12) of the
saddle (2) and the frame (5).
2. A railway tank car according to claim 1, wherein the upper edge (13) of the side wall
(11) in the saddle (2) is welded on a pad (3) of the railway tank (1).
3. A railway tank car according to claim 1, wherein a gap between the base (12) of the
saddle (2) and the frame (5) is closed by a spacer (18) made of any material of one's
choice.
4. A railway tank car according to claim 3, wherein the spacer (18) is flexible and made
of plastic, preferably polypropylene.
5. A railway tank car according to claim 1, wherein the length of the base (12) in the
saddle (2) is substantially smaller than the maximum dimension which is the chord
of the upper edge (13) of the side wall (11) in the saddle (2).
6. A railway tank car according to claim 1, wherein the spacer (18) is similar in shape
to the rectangular base (12) of the saddle (2).
7. A railway tank car according to claim 1, wherein lugs (23) provided at both ends of
the railway tank (1) on its both sides, are welded at the bottom to a turning beam
(7) of the frame (5) and, at the top, to a strip (19) of the railway tank (1).
8. A railway tank car according to claim 1, wherein one of side walls (11) and a base
(12) of the saddle (2) are formed of rolled angle (16), whereas the other side wall
(11) of the saddle (2) is formed of sheet metal (17), and those parts are joined by
a weld at the base (12) of the saddle (2).
9. A railway tank car according to claim 1, wherein the axis of symmetry (9) of each
saddle (2) is shifted towards the centre of the railway tank car, in relation to the
vertical axis (10) of the two-axle truck (4) of the railway tank car.