Included in this section are special-purpose Shunts or shunt-like products utilizing the traditional head and base of rail clamps.
Unbalanced Track Circuits – Unbalanced track circuits occur on all types of railroads. Their results can be damaging to shunts on electrified railroads. S&C has configured a unique series of shunts identified by the part number prefixes 550 and 559. If unbalanced your shunts you will probably want to specify these types. Substitute the 550 part number prefix for the 506 prefix for standard Clamp Shunts, and 559 prefix for the 5069 prefix for Clamp Shunts with Strain Reliefs, on any of our Shunt ordering references.
Easy to use tool for maintaining and trouble-shooting AC/DC, Style C Track Circuits. Our 506-XXRS Circuit Maintenance Tool includes a specified resistance value (usually 0.06 ohms) and zero ohm shunts for making adjustments and testing track circuits for proper train detection. It also includes a diode to allow you to use the Tool as a substitute diode for determining the source of the failure causing the warning lights and bells to ring without a train present. Base of rail clamps are recommended for this tool.
ORDERING REFERENCES
(Insert resistance value .06, .07, .10, .12, .15, .18, .20, .25 where blanks in parenthesis are shown, omitting decimal. Note that for virtually all freight railroad applications, .06 ohms is the correct value)
506-XXRS Tool with
Base-Of- Rail Clamps
Single resistance & Zero . . 506-(_ _)RSB
506-XXRS Tool with
Head-Of-Rail Clamps
Single resistance & Zero . . 506-(_ _)RSH
Designed specifically for calibrating GCP-4000 (r) island circuits. Includes the five resistances required for proper calibration of the island circuit, at the island circuit track wire connections to the rail. Base of rail clamps are recommended for this shunt.
ORDERING REFERENCES
| ITEM NO | DESCRIPTION | ORDERING REFERENCE |
| A | Shunt, 5 Resistance; .06,.12,.30,.40,.50 Base of Rail Clamps, Bag | 506-612345BZ |
| B | Above, but Head of Rail Clamps, Bag | 506-612345HZ |
Rugged, traditional, clamp-type shunt for commissioning, adjusting and testing track circuits. Special resistance combination: 0.06 ohm standard resistance value used for most track circuits and a special 0.07 ohm resistance for accommodating a new Alstom(r) track circuit. Our unique design assures extremely low probability of resistance variations within the shunt assembly. Switchable between the stated testing values (.06 & 0.07 ohms) and zero ohms with gold test nut switches.
Options include:
ORDERING REFERENCES
Black (B) Wire Is furnished unless requested otherwise. Other choices are Red (R), Safety Orange (A) and Brite Yellow (Y). To specify optional color add alpha character (R, A and Y) in parenthesis shown below in the ordering reference . Add “Z” to end of ordering reference to indicate Heavy Duty Shunt Carry Bag
| REF | DESCRIPTION | BASE OF RAIL CLAMPS | HEAD OF RAIL CLAMPS |
| A | Shunt with 0.06, 0.07 & Zero Ohm Resistances | 506-067(_)B | 506-067(_)H |
| B | Above, but with “Open” capability | 506-067O(_)B | 506-067O(_)H |
| C | Ref A, but with Strain Reliefs at clamp ends | 509-067(_)B | 509-067(_)H |
| D | Ref B, but with Strain Reliefs at clamp ends | 509-067O(_)B | 509-067O(_)H |
Used for activation testing of audio overlay and motion-responsive, electronic crossing warning system control circuits and to temporarily block such circuits from being activated by track work within the approaches. Will not interfere with properly adjusted DC circuits. Cannot be used for adjustment of track circuits. Well-proven, Probe style shunt is recommended for activation testing because it cannot be forgotten in a condition where it causes problems. Base of Rail Clamps only recommended if operating circumstances require them. Also available with Head of Rail Clamps, Web of Rail Clamps, and Warren Fast Shunt Clamps with 14, 24 and 38 inch handles. Please note that out of an abundance of caution, it is the practice of S&C Distribution Company, to call the person to whom an AC-only shunt with rail clamps is being shipped, to ensure that he understands the nature of the product he will be receiving.
ORDERING REFERENCES FOR AC-ONLY SHUNTS
Shunt with Probes . . . . . . . . . . . . . . .PN: 516-P
Shunt with Head Clamps . . . . . . . . . .PN: 516-H
Shunt with Web-of-Rail Clamps . . . . PN: 516-WOR
Shunt w/14 in. Handles . . . . . . . . . . . PN: 506WFS-AC
Shunt w/24 in. Handles . . . . . . . . . . . PN: 506WFS24-AC
Shunt w/38 in. Handles . . . . . . . . . . . PN: 506WFS38-AC
Shunt with Base of Rail Clamps . . . . .PN: 516-B
Selectable AC-only, Resistance and Open testing capabilities are offered by the S&C Combo Shunts. The Combo Shunt can perform all the normal track circuit adjusting and test shunting activities performed by signal maintenance and construction personnel. In addition, in the AC mode, it can be used to check the operation of overlay and motion responsive track circuits without interfering with DC train control circuits, The Open option has been used by railroad signal personnel to create a “dirty” shunt that will cause motion sensitive and constant warning time devices to go into detection, and is available in the single-resistance configuration.
These Shunts come in several Resistor Block configurations:
We offer these shunts with head, web of rail and imbedded rail clamps, Warren Fast Shunt handles of 24 and 38 inches, and track probes. They can also be purchased, by special request, with base of rail clamps. Please note that out of an abundance of caution, it is the practice of S&C Distribution Company, to call the person to whom a Combo Shunt with rail clamps is being shipped, to ensure that he understands the nature of the product he will be receiving.
ORDERING REFERENCES FOR COMBO SHUNTS
Specify resistance value desired by replacing parenthesis in ordering reference with value. Shunt resistances available include 0.06, 0.07, 0.10, 0.12, 0.15, 0.18, 0.20, 0.25, 0.50 and 2.0 Ohms (use “5X & 2X” in ordering references below to signify “0.50 & 2.0” Ohms).
| REF | DESCRIPTION | PART NUMBER |
| 7-A1 | Shunt w/AC and Open, Head Clamps | 518ACO-H |
| 7-A1A | Shunt w/AC and Open, Web of Rail Clamps | 518ACO-WOR |
| 7-1 | Shunt w/AC, 1 res., Open & Head Clamps | 518-( _ _ )O-H |
| 7-2 | Shunt, above but with 2 resistances | 518-( _ _ )-( _ _ )-H |
| 7-3 | Shunt w/AC, 1 res., Open & Web Clamps | 518WOR-( _ _ )O |
| 7-4 | Shunt, above, but with 2 resistances | 518WOR-( _ _ )-( _ _ ) |
| 7-5 | Shunt w/AC, 1 res., Open & Probes | 518P-( _ _ )O |
| 7-6 | Shunt, above, but with 2 resistances | 518P-( _ _ )-( _ _ ) |
| 7-7 | Shunt w/AC, 1 res., Open & Files | 518F-( _ _ )O |
| 7-8 | Shunt, above, but with 2 resistances | 518F-( _ _ )-( _ _ ) |
| 7-9 | Shunt w/AC, 1 res., Open & Imbed Clamps | 518I-( _ _ )O |
| 7-10 | Shunt, above, but with 2 resistances | 518I-( _ _ )-( _ _ ) |
| 7-11 | Shunt w/AC, 1 res., Open & WFS 38 in hdls | 518FS38-( _ _ )O |
| 7-11A | Shunt w/AC, 1 res., Open & WFS 24 in hdls | 518FS24-( _ _ )O |
| 7-12 | Shunt, above, but with 2 resistances, 38 in. hdls | 518FS38-( _ _ )-( _ _ ) |
| 7-12A | Shunt, above, but with 2 resistances, 24 in. hdls | 518FS24-( _ _ )-( _ _ ) |
| 7-13 | Shunt w/AC, 1 res.,Open, WFS38 & Meter | 518FS38S-( _ _ )-OV |
| 7-14 | Shunt Wire Retro-Fit, w/AC, 1 res. & Open DO NOT use with base of rail clamps | 518-( _ _ )O-1 |
| 7-15 | Shunt Wire Above, but with 2 resistances DO NOT use with base of rail clamps | 518-( _ _ )-( _ _ )-1 |
Many railroads, particularly those oriented toward passenger transit, have a need for precise track circuit tests and adjustments. Multiple resistance shunts have been developed for this purpose. Most such shunts require various combinations of resistance values to “build” the resistances required.
S&C Distribution Company has simplified the process by supplying the most commonly required range of nine resistances in a protective, easy-access bracket (shown above). Each of the resistances is individually made active by opening a gold nut test switch. Values furnished are zero (hardwire), .06, .10, .15, .20, .25, 1.00, 1.20, 1.30 and 1.40 ohms. Additional resistances can be “built” by opening combinations of switches. An “Open” is also furnished. Additional low-resistance values available as substitutes are 0.12 and 0.18 ohms. We will build this shunt with whatever resistance values meet your needs. Contact us for details and pricing.
ORDERING REFERENCES
The below ordering references all call for the standard resistance configuration as stated on the first page of this brochure. Any combination of resistances, up to ten is available as a Multi Shunt. Select resistances from the table on the first page of this brochure and contact us for an ordering reference. To specify wire color other than black add the designator to the end of the ordering reference, as follows: Safety Orange (A); Red (R); Yellow (Y)
| Description | Ordering Reference |
| 506M Shunt, std Resistances with base-of -rail clamps | 506M-006B |
| 506MS1 Shunt with base-of -rail clamps, w/Strain Reliefs | 509M-006B |
| 506MS1 Shunt with head-of-rail clamps | 506M-006H |
| 506MS1 Shunt with head-of-rail clamps, w/Strain Reliefs | 5069M-006H |
| 506MS1 Shunt with web-of-rail clamps | 506M-006W |
| 506MS1 Shunt with imbedded rail clamps | 506M-006I |
| 506MS1 Shunt with Track Probes | 506M-006P |
| 506MS1 Shunt with 38 in. Warren Fast Shunt Handles | 506M-006FS38 |
| Shunt Bag for MS1 Shunt with BOR, HOR Clamps | 506ZB |
| Shunt Bag for MS1 Shunt with WOR and Imbedded Rail Clamps, and Track Probes | 506BZB |
| Shunt Bag for MS1 Shunt with 38 in. Warren Fast Shunt Handles | 506ONBZB-38 |
