Rail crossing assembly

A railroad trackwork rail crossing having four rail intersection corners is comprised, at each corner, of four corner casting elements which have angled planforms, co-operating straight intermediate rail elements, co-operating straight guard rail elements, cooperating straight traffic rail elements, and bolt fasteners joining the casting and rail elements into a rigid unitary rail crossing structure.

FIELD OF THE INVENTION 
This invention relates generally to railroad trackworks, and particularly 
concerns a novel rail crossing assembly which obtains substantial 
manufacturing and operating maintenance economic advantages in comparison 
to known rail crossing constructions. 
BACKGROUND OF THE INVENTION 
Most rail crossings incorporated in railroad trackworks constructed in the 
United States are classified into one of three different design types. The 
three-rail rail crossing design of American Railway Engineering 
Association (AREA) Plan No. 701, for example, was once extensively 
utilized. However, utilization in recent years has diminished in view of 
the availability of newer and improved rail crossing designs and in view 
of the heavier rail loadings, heavier trackwork traffic density, and 
higher railcar operating speeds that are typically now being encountered 
in the industry. Three-rail design (and even its two-rail variation) rail 
crossings normally are not weld-repairable in the field, such as to 
correct for excessive rail wear, because of the need for closely 
controlled preheating and postheating of the rail steel. Also, a 
requirement for the replacement of failed crossing components with custom 
machined parts makes field repair of this type of rail crossing assembly 
both quite difficult and costly. 
The solid manganese rail crossing design of AREA Plan No. 771 is frequently 
incorporated into trackwork constructions and does have the advantage of 
being field-weldable to restore worn or damaged crossing surface areas. 
However, this particular type of rail crossing is characterized by high 
initial manufacturing cost. This type of rail crossing's end frog castings 
may be interchanged, but such is seldom undertaken because each typically 
experiences an equal amount of wear. The same consideration also applies 
to the design's included center frog castings. 
The third type and the most-widely used rail crossing construction in the 
United States at the present time is believed to be the reversible 
manganese insert rail crossing of AREA Plan No. 747. The unique 
configuration of the one-piece insert casting included at each corner of 
the rail crossing in this construction requires that all of the 
additionally included external rail components have one bend and that all 
of the also included internal rail components have two bends. Such bends 
are difficult to control in manufacture as to fit and retained hardness 
and thus are costly to make and normally are not repaired in the field. 
We have discovered a novel rail crossing construction that overcomes the 
shortcomings associated with the known rail crossing assemblies 
incorporated in railroad trackworks utilized in the United States. Other 
advantages of the present invention arise out of the elimination of 
included rail bends, the minimization of corner casting size to effect a 
reduction in foundry material and labor costs, the ability to repair the 
crossing in the field and the simplification of assembly component 
machining requirements. Still other objects and advantages of the present 
invention will become apparent from a careful consideration of the 
descriptions and drawings which follow. 
SUMMARY OF THE INVENTION 
The rail crossing assembly of the present invention has four corners 
(sometimes separately identified by different letters or numbers), and 
each corner is basically comprised of four corner castings which are 
joined but in spaced-apart relation to form intersecting rail car wheel 
flangeways. In the case of a right-angled rail crossing assembly 
configuration, the four corner castings are made identical in planform; in 
the case of an oblique-angled rail crossing assembly configuration, the 
four corner castings are comprised of two acute-angled planform corner 
castings co-operating with two supplementary obtuse-angled planform corner 
castings. 
The joined outboard ends of each co-operating pair of corner castings in 
the assembly are joined to a respective straight traffic rail element and 
to a respective straight guard rail element. The joined inboard ends of 
each co-operating pair of corner castings are joined to a pair of 
spaced-apart, straight intermediate rail elements. Joining of the rail 
crossing assembly corner castings, straight intermediate rail elements, 
outboard traffic rail elements, and outboard guard rail elements into a 
unitary, rigid structure is preferably accomplished using properly sized 
and positioned filler elements and threaded nut and bolt fasteners to 
establish the rail car wheel flangeways required by the assembly. 
It is important to note that the corner casting elements of the rail 
crossing invention need not necessarily be cast using a manganese steel 
material; other types of steels such as the highstrength, low-alloy 
steels, bainitic steels, and eutectoid steels utilized in the industry are 
more likely to be better suited for most rail crossing construction 
applications that are now anticipated.

DETAILED DESCRIPTION 
FIGS. 1 through 3 of the drawings illustrate details of a representative 
reversible manganese steel insert type of rail crossing assembly now being 
widely utilized in railroad trackwork systems throughout the United 
States. Such rail crossing assembly is commonly identified as an AREA Plan 
No. 747 manganese steel insert crossing, is referenced generally by the 
numeral 10 in the drawings, and is comprised of four reversible manganese 
insert corner castings 12 through 18, of eight outboard bent traffic rail 
elements 20, of eight outboard bent guard rail elements 22, of eight bent 
intermediate rail elements 24, of eight obtuse corner strap elements 26, 
of eight acute corner strap elements 28, and of numerous filler elements 
30 that all are joined into a unitary, rigid assembly having continuous, 
straight-line wheel tread support surfaces and continuous, straight-line 
and intersecting wheel flangeways 32, 34, 36, and 38. The various included 
bolt and nut fasteners join components 12 through 30 together. The adjunct 
support ties, base plates, and rail fasteners, which complete a typical 
rail crossing installation are not shown in the drawings. Section views 
taken at lines 2--2 and 3--3 of FIG. 1 are provided in FIGS. 2 and 3, 
respectively. 
A preferred embodiment of the present rail crossing assembly invention is 
illustrated in two different planform configurations in FIGS. 4 and 5 of 
the drawings. Assembly 100 of FIG. 4 is a rail crossing assembly for a 
right-angled track intersection; assembly 200 of FIG. 5 is an assembly 
similar to rail crossing assembly 100 but for an oblique-angled track 
intersection. The least angle of intersection of the assembly traffic 
rails is typically in the range of 45.degree. to 90.degree. but in some 
applications may be more acute. 
As shown in FIGS. 4 and 5, each rail crossing assembly 100 or 200 has four 
corners, and each corner is basically comprised of four spaced-apart but 
mechanically joined together corner castings. In the case of assembly 100 
the four corner castings are referenced as 102 through 108 and each has 
the same right-angled planform, overall configuration, and size. In the 
case of assembly 200 the four corner castings are referenced as 202 
through 208 with corner castings 202 and 204 having acute-angled 
planforms, and corner castings 206 and 208 having supplementary, 
obtuse-angled planforms. Each individual corner casting in each rail 
crossing corner assembly is spaced apart from its adjacent, co-operating 
individual corner casting by the width of the assembly car wheel flangeway 
110 or 210 as hereinafter described. Additionally, each corner casting 102 
through 108 (202 through 208) has one or two inboard ends 117 (217) which 
engage an intermediate rail element (112, 114) or (212, 214) and/or one or 
two outboard ends 119 (219) which engages one of a traffic rail element 
118 (218) and guard 116 (216) rail element. 
Each inboard end 117 (217) of an individual corner casting 102 through 108 
(202 through 208) in the rail crossing corner has a relatively straight 
flat planar vertical surface 121 (221) which co-operates with a straight 
flat planar vertical side 123 (223) at one end of a respective one of a 
pair of straight, spaced-apart intermediate rail elements 112 and 114 
(FIG. 4), or 212 and 214 (FIGS. 5-7). Each outboard end 119 (219) of an 
individual corner casting 102 through 108 (202 through 208) in a rail 
crossing corner has a relatively straight flat planar vertical surface 125 
(225) which co-operates with a straight flat planar vertical side 127 
(227) at one end of a respective straight guard rail element 116 (or 216) 
or straight traffic rail element 118 (or 218). Each cooperating pair of 
traffic rail and guard rail elements in the rail crossing assembly is 
spaced apart by the width of the railcar wheel flangeway specified for 
that assembly. Also, and as will be later detailed, we prefer that the 
ends of all such rail elements have a mitered cut configuration that upon 
assembly abuts correspondingly mitered rail abutment surfaces respectively 
provided in each corner casting 102 through 108 or 202 through 208. 
Each of assemblies 100 and 200 include multiple flangeway filler castings, 
including corner filler elements 120 and 220 installed in the rail 
crossing corners between the included intermediate rail elements, flared 
end filler elements 122 and 222 installed in the assemblies between each 
pair of co-operating traffic rail and guard rail elements, and guard chuck 
filler elements 124 and 224 also installed between each pair of 
cooperating traffic rail and guard rail elements. Threaded bolt and nut 
fasteners 126 and 226 of appropriate length, and preferably in accordance 
with AREA specifications for applicable special trackwork, are utilized 
throughout assemblies 100 and 200 to effect proper joinder of components 
102 through 124 and components 202 through 224 into their respectively 
illustrated configurations. Such fasteners, for clarity of illustration 
purposes, are shown and detailed in the drawings only in connection with 
the included section views. See FIGS. 6 and 7, for instance. 
FIG. 8 schematically illustrates the planforms for the corner casting 
elements incorporated into assemblies 100 and 200, e.g. corner castings 
having application to rail crossings with an intersection angle of 
approximately 90.degree. (FIG. 4) or 60.degree. (FIG. 5). Corner castings 
102 through 108 each have the included angle B (90.degree.) intermediate 
the flangeway faces 300 of the casting; acute-angled corner castings 202 
and 204 for the 60.degree. crossing intersection have the included angle A 
(60.degree.), and the obtuse-angled corner castings 202 and 208 for that 
rail crossing intersection have the supplementary angle C (120.degree.). 
It should also be noted that the assembly corner casting elements are each 
provided with cast-in-place fit pads 302 that may be subsequently machined 
to a closely-dimensioned height to assure a proper fit-up of the casting 
to its co-operating guard rail/traffic rail elements on final assembly. 
Most rail crossing installations utilized in the United States are custom 
designed to an exact angle of intersection to suit a specific site in a 
railroad trackwork system, and in most instances the angle of intersection 
is a specific angular value generally in the range of from 45.degree. to 
90.degree.. 
FIG. 9 is included in the drawings to more clearly illustrate that each 
corner casting in the rail crossing assembly of the present invention also 
preferably includes sloped "easer" ramps 304. See also FIG. 8. Each such 
easer slope or ramp element is conventional and is provided in rail 
crossing castings to minimize the impact loadings that would otherwise 
occur when the false flanges of a worn railcar wheel first contact the 
corner casting during a crossing operation. 
FIG. 10 is provided in the drawings to illustrate the manner whereby the 
rail crossing assemblies of the present invention may be modified to be 
compatible with a somewhat increasingly desired flange-bearing mode of 
railcar wheel crossing operation. Basically the configuration of each 
corner casting 202 thru 208 in the assembly can be modified to allow the 
flangeway fillers 220 to be extended throughout the full length of each 
corner of the crossing to the extreme ends of the castings 202 and 206. 
The normal depth of the top horizontal surface of a flangeway filler 230 
is designed to provide clearance for a normal wheel flange 242 as 
illustrated in FIG. 11. This allows the tapered tread 244 of a wheel 240 
to contact the top running surface 306 of the crossing castings as is 
conventional industry practice. See FIG. 9. Since the deterioration due to 
wear and impact is normally imparted to the top surface 306 by the wheel 
tread 244, it is desirable to minimize or eliminate this as a contact 
point. By providing an upwardly tapering sloped surface 232 to the end 
portion 230 of flangeway filler 220 as seen in FIG. 10, the wheel flange 
is gradually elevated as it passes through the entry end of the corner on 
sloped surface 232 until it reaches the upper end of the sloped portion. 
Here it assumes an elevated position with flange 242 riding on and in 
contact with the horizontal flangeway filler surface 234. This now allows 
the wheel 240 and its corresponding tread surface 244 to become elevated 
above the top running surface 306 of the crossing as shown in FIG. 12. 
This is desirable as it allows the wheel 240 and corresponding wheel tread 
surface 244 to pass over and above the intersecting flangeway gap 210. 
This eliminates the sudden impact between wheel tread 244 and the top 
running surface 306 of the corner casting 202-208, which is the cause for 
wear, damage, and failure of crossing castings in normal existing 
configurations. The wheel 240 and corresponding tread surface 244 are then 
allowed to return to their normal elevation as they exit the corner of the 
crossing due to the downwardly sloping surface 232 at the opposite end. 
From the above it may be seen that the design allows for wheel elevation 
to be provided in both directions as the surface path of the top of the 
filler 230, 232, 234 is symmetrical at each corner location. 
Utilization of the flangeway filler top surface to impart the flange 
bearing action is very desirable as the costly crossing corner castings 
202 thru 208 do not have to be enlarged. The relatively inexpensive 
flangeway filler 220 can be further extended beyond the limits shown to 
provide for a longer more tapered sloped surface 232 thus allowing for a 
more gradual transition of the wheel elevation in higher speed 
applications and where smoother ride is desirable. As the top surface 234 
of the flangeway filler becomes worn due to service it looses its 
elevating effectiveness, in this configuration the filler itself can be 
easily replaced to further extend the life of the crossing assembly. 
The advantages of the present invention may be restated as including, at 
each rail crossing corner, four separate corner casting elements that 
necessarily need not be made of a manganese steel and that provide twice 
the number of reversing options in comparison to the prior art reversible 
casting rail crossing constructions. Additionally, the rail crossing 
construction utilizes no bent rail elements and does not contain a 
flangeway floor portion which has been prone to cracking failure due to 
stress concentration in this area on existing designs. Because the novel 
construction does not contain any bent rail elements it is not necessary 
to have any special beveled headlocks or beveled washers to accommodate 
bolt fasteners and permits the use of bolt fasteners which are of the same 
length throughout the entire assembly. Also, no special bent and machined 
corner strap elements are required to develop assembly unity and rigidity 
as that is accomplished by the corner castings themselves.