2012 NMRA Convention - Grand Rapids logo
national train show

RP-37.1 Locomotive - Tender Drawbar and Pin Dimensions

RP-37.1

This sheet establishes the "standardized" dimensions of locomotive Drawbars and tender pivot Pins to support the relationships of RP-37.

RP37.1-2

To assure positive electrical contact between the Drawbar and the tender pivot Pin, a wire spring may be soldered to the Drawbar so as to lie across both holes, thus bearing with spring pressure against the Pin when it is inserted in operating position.

Materials used for the Drawbar and its spring wire should be electrically conductive such as Brass or Nickel-Silver. Nickel plating of the Brass will prevent oxidation.

DRAWBAR DIMENSIONS
Scale Height
DH		 Width
DW		 Thickness
DT		 Hole Dia.
DD		 Hole Centers
CC		 Wire Dia.
WD
O
On3
S
Sn3
HO 5/16" 11/64" .040" #45 drill (.082) 5/32" .022"
HOn3
TT 17/64" 1/8" .032" #51 drill (.067) 1/8" .022"
TTn3 7/32" 1/8" .032" #51 drill (.067) 1/8" .022"

RP37.1-3

TENDER PIN DETAILS

The tender pivot Pin should be mounted to the tender floor so as to clear the railhead by the amount specified in the Table below and setback from the tender end sill by the amount specified in RP-37. Mounting may be threaded as shown, or firmly soldered in place, to be in conductive connection to tender trucks. If the tender floor height varies from that shown, Pin length should be modified to suit.

Material used for the Pin should be electrically conductive, such as Brass or Nickel-Silver. Nickel plating of the Brass will prevent oxidation.

TENDER PIN DIMENSIONS

Scale Clearance
PC		 Diameter
PD		 Length
PL		 Taper
PT		 Flange
PF		 Mounting
PM
O
On3
S
Sn3
HO 3/32" .078" 11/32" 3/32" 5/32Hex x 3/64 2-56Th'd x 3/64
HOn3
TT 5/64" .062" 9/32" 1/16" 7/64Hex x 3/64 1-72Th'd x 1/16
TTn3 5/64" .062" 13/64" 1/16" 7/64Hex x 3/64 1-72Th'd x 1/16