Modular Liquid Collection System for Railroad Roadbeds

It is desirable, from the standpoint of both pollution abatement and economics, to collect and salvage the diesel fuel spilled at railroad fueling stations. In the past, two types of collection systems have been used for this purpose. The first type uses permanent concrete pits and aprons. This apparatus is quite expensive, and its construction requires considerable time. The second kind of collection system is modular in nature and employs a series of pans made of sheet metal or fiberglass which are installed on the ties, and cross drains of similar material which are positioned between the ties. While these modular systems can be installed more easily and are less costly than the permanent systems, they too have undesirable characteristics. The chief disadvantages are:

A. The use of specialized components which usually cannot be obtained or fabricated in the locality of the fueling station.

B. A relatively large number of separate components.

C. The lack of durability.

D. The need for including costly metal gratings to provide secure footing for railroad crews.

E. The necessity, in some instances, to drill attachment holes in the rails and to take special measures to provide electrical insulation.

The object of this invention is to provide an improved form of modular liquid-collecting system. According to the invention, the modules employ precast components made of reinforced concrete or foamed plastic which are retained in place by reason of their own weight and shape and without the need for special rail or tie attachments. Each module comprises at least one basin which rests on the ties, and a cross drain which is posititioned in the ballast between ties. A complete module comprises three basins, one being designed to fit between the rails and other being designed for use at the outboard sides of the rails. All basins are formed with integral, depending locking means which coact with tie side faces to limit movement of the basin in the direction of the rails, and with a liquid receiving surface defined by four planar faces which slope downward toward a centrally located drain opening which overlies the cross drain. The side or outboard basins are formed with integral longitudinal curbs, and separate, removable end curbs are provided for the terminal modules of an end-to-end series.

The new modular collection system is especially desirable because it is inherently durable, requires only a few components which can be fabricated locally by railroad personnel using readily available materials, and can be installed quickly and easily on existing roadbeds. In addition, the basins themselves are self-draining and otherwise inherently provide secure footing, so auxiliary gratings are not needed. Finally since the components are electrically non-conductive, they are inherently safer for the workmen and can be installed on signaled track without any modification.

The preferred embodiment of the invention is described herein with reference to the accompanying drawings, in which:

FIG. 1 is a plan view of a portion of a roadbed incorporating the improved collection system.

FIGS. 2-5 are enlarged sectional views taken on lines 2--2 to 5--5, respectively, of FIG. 1.

FIG. 6 is an enlarged view of a portion of FIG. 4.

As shown in the drawings, the new modular collection system in its fullest is applied to a roadbed which includes a pair of welded rails 11 and 12 which are carried by tie plates 13 attached to switch ties 14 embedded in compacted ballast (not shown). The system comprises a series of modules, two of which are illustrated at A and B, arranged end-to-end along the roadbed. Except as noted below, the modules employ identical components. Therefore, corresponding parts are identified by the same reference numerals, with postscripts a and b being used to distinguish one set of parts from the other.

Collection module A comprises a basic set of four precast components, namely, a central basin 16a, two outboard basins 17a and 18a, and a cross drain 19a. These parts, as well as the other precast elements of the system mentioned later, are made of concrete and are reinforced by steel rods indicated generally by the dot-dash lines and solid circles 21a. Central basin 16a is of rectangular shape in plan view and has a length equal to a multiple (e.g. 5) of the centerline spacing of ties 14. The width of basin 16a is slightly greater (for example, 1 inch greater) than the transverse distance between the heads of rails 11 and 12, so that the unit can be fitted into the space between the rails, yet have its sides closely adjacent the rail webs. The height of the basin is so chosen that the upper side corners are positioned opposite the head-web fillets of the rails.

Basin 16a is formed with a flat, planar bottom surface 22a over most of its area in order that it will rest securely on the upper faces of the ties. However, adjacent each end, this component is provided with an integral, depending locking projection 23a (see FIG. 4) which fits between a pair of adjacent ties 14 and engages the oppositely directed side faces of those ties. This arrangement prevents any substantial shifting of the basin in the direction of the rails. The bottom of basin 16a also is formed with a recess 24a which extends longitudinally along each side, and which provides clearance for the adjacent rail base, tie plate 13 and spike heads (not shown).

The upper, liquid-receiving surface of basin 16a is defined by four planar faces 25a-28a which slope downward from the basin margins and converge toward a centrally located drain opening 29a extending through the unit. The size of the basin and the pitch of these faces is selected to insure runoff of liquid, to thereby preclude the formation of pools. As shown in FIG. 6, the drain opening preferably is fitted with a perforated plate strainer 31a, from which depends a waste pipe 32a.

The outboard basins 17a and 18a are sized to cover most of the exposed area of ties 14 at the outboard sides of rails 11 and 12, respectively, without overhanging the ends of the ties. These units are illustrated as indentical, but one may be wider than the other depending upon the requirements of a particular installation. In any event, they have the same length and height as central basin 16a and are constructed in a similar way. Thus, each outboard basin includes a flat, planar bearing face 33a or 34a which engages the upper surfaces of the ties, integral locking projections 35a or 36a, a clearance recess 37a or 38a running along the side adjacent the rail 11 or 12, a liquid-receiving surface defined by a set of four planar, sloping faces 39a, 41a, 42a and 43a or 44a, 45a, 46a and 47a, and a central drain opening 48a or 49a equipped with a strainer and waste pipe. However, in contrast to central basin 16a, each of the outboard basins is formed with an integral curb 51a or 52a which extends longitudinally along the upper margin of its exposed side and which projects above the liquid-receiving surface. Although, because of their size and weight and the inclusion of locking projections, the outboard basins require no auxiliary fasteners to hold them in place, as a safety precaution it is recommended that they be restrained against transverse movement away from the rails by spikes 53a driven into the ties alongside the basins.

The cross drain 19a of module A is simply a trough with closed ends which rests in the ballest between an adjacent pair of ties 14 and below the drain openings 29a, 48a and 49a of the three basins. The drain extends about 2 feet beyond the ends of the ties at one side of the roadbed, and near its end it is formed with a bottom discharge opening 54a. This opening is fitted with a waste pipe 55a which is joined to a common collection pipe (not shown) that runs in the direction of the roadbed and interconnects the various modules. Since, as indicated in FIG. 2, the cross drain 19a is below ground level, the portion outboard of basin curb 51a is covered by a treated wood plank 56a.

Referring to FIG. 5, it will be observed that the end faces of the basins are beveled to provide a wedge-shaped gap at the junction between abutting modules. The gap has a maximum width of about one-half inch, and is sealed by a suitable oil resistant compound 57 which overlies a caulked backing 58.

The terminal modules of the series, of which module A is one, are provided with removable, precast curbs 59a, 61a and 62a which extend across the exposed ends of the basins 16a, 17a and 18a, respectively. These curbs are of L-shape in cross section, each having a horizontal leg which rests at its side on the associated basin and a vertical leg which bears endwise against the top of the underlying tie 14. As in the case of the basins themselves, the depending legs of the removable curbs are formed with recesses to provide clearance for the rail bases and the tie plates. Each of the curbs 61a and 62a extends across practically the full width of the associated outboard basin 17a or 18a, but the center curb 59a is made considerably shorter than the width of basin 16a in order to provide clearance for the flanges of the train wheels. Inclusion of the curbs, both integral and removable, is desirable because these parts prevent overflow in the event of massive spillage, and also because they tend to keep the basins free of dirt and gravel.

In the interests of minimizing the risk of escape of diesel fuel from the collection system, it is desirable to provide some sort of seal between the rails and the adjacent margins of the basins. The illustrated modules include such seals, each of which takes the form of a length of neoprene hose 63a which is compressed between the head-web fillet of the rail and the adjacent upper basin corner.

The recommended concrete mix for the precast components employs Type III cement and an agregate having a maximum size of 1/2 inch, and has approximately 7 percent entrained air. This mix provides a compressive strength of 2,000 p.s.i. at 3 days and 5,000 p.s.i. at 28 days. It is also recommended that the exposed edges of both the integral and the removable curbs be slightly rounded, and that the upper surfaces of all basins be given a slightly rough, anti-skid finish. Finally, since the basins are relatively heavy, each should be provided with a set of inserts 64a into which the eye bolts used for power hoisting can be threaded.

Although it is presently preferred that the precast parts be made of concrete, the foamed plastic used as a substitute for concrete in railroad crossings may be employed.

This change would substantially reduce the weight of the parts, but only at the expense of increasing cost, and also perhaps making local fabrication impractical. It also should be observed that, while the illustrated system employs complete modules, i.e., modules having three basins, it will be evident that any basin or combination of two basins could be used in situations where the liquid-collecting capability of such a simplified arrangement is deemed sufficient.