Consolidated Rules for SSMBC "Springer Tugs"

This page was updated on September 14, 2019

Forward

     A "Springer" tug is a one design class model boat.  Rules have been created for many "Springer Tugs" worldwide.  However, many have gone well beyond the original "rules" for Springer Tugs.  Different sizes, multiple motors, and other deviations are out there.  It is the intent here to limit modifications to the original "rules" in a small way to accommodate modern model boating.  This will be noted below in red with *SSMBC*.

SSMBC Rules, regulations and Specifications for Springers Tugs

1. The Basic Hull

  Hull Profile to conform to original Springer profile. Beam is 8 inches” +- .062, Length 18 inches +- .125”
Push Knees – ¾ inch wide, minimum 2 ½ inches in height measured from deck, mounted on 7-inch centers.  Knee may be flush with hull's bow, or extend out from the bow a maximum of 1/2 inch (including a bumper pad) *SSMBC*.  The knee may extend down below the waterline (but may reduce performance if too deep).  *SSMBC*
Weight – 8 ½ lbs. minimum.
Soft Bumper *SSMBC* (foam or rubber/vinyl) around the perimeter of the hull will be permissible.  This cannot exceed 3/16 inch out from the hulls sidewalls (plus aft and forward bulkheads. The height would be from flush with the main deck down the a maximum of 1/2 inch from the deck. (See drawing at the right.)  This is to add some protection against other boats or objects.

2. The Hull External Items (Rudder, Propeller)

Conventional Propeller shall be 3 bladed and no larger than 44mm in diameter.  (Expanded from 40 to 44mm because of propeller supplied with Zippkits. *SSMBC*)  (No Kort nozzles or Z drives are permitted.)
Rudder (only one) shall be a maximum area of 4 square inches (salmon tail allowed).  Rudder shall be one piece with no individual moving parts.  Rudder must not exceed past transom (rear of hull).
Rudder Shoe (Mandatory for boat playing sports where a roped barrier is used (i.e. water polo) for course boundaries.  All boats must be equipped with a rudder shoe that extends from the skeg or hull bottom to the rudder shaft.  The shoe must be 1/16 inch or less from the rudder in order to prevent the rudder or propeller from snagging a ¼ inch rope.  Recommended to reduce weed tangling

3. The Hull Internal Items (Motors, Batteries, Electronics, etc.)

Battery of 6 Volts shall power the motor.  A 7.2 volt standard hobby batteries are allowable.  (Substitution of the 6 volt batteries allowed because of the availability of the 7.2 volt batteries and most modelers use them in other boats. *SSMBC*)
Motor Type – Builders option.
Gearing – Builders Option, but must drive a single shaft direct or reduced drive to the propeller.

4. Above Hull External Items (Superstructure, etc.)

The cabin and other features on or above deck will be left to the discretion of the builder.  There are no rules as to scale and style.  Many types are out there from scale, bizarre, comical, exaggerated, and more.

Team Flag and Flag Holder – 1 inch 3/32 inch brass tube centered on stern approx. ¼ inch from edge.  Alternate identification can be used. *SSMBC*

Door Stops – Removable spring type mounted facing forward centered horizontally on each knee and vertically at or below deck level (to hold ball).