By authority of RCW 46.37.005 and 46.37.320, the state patrol hereby adopts the following regulations pertaining to vehicle connecting devices and towing methods.

The purpose of this regulation is to provide this state with a uniform minimum requirement for motor vehicle connecting devices and towing methods. This regulation is not intended to cover the fifth wheel type of connecting device or towing method. Pintle hook type devices will also be excluded from this chapter, except that the safety chain requirements will apply.

(1) The scope of this regulation is directed to the regulation of trailer hitches and towing devices, towing methods, testing methods, certification requirements, installation, compliance and other requirements as herein defined in these regulations used for drawing a trailer or semitrailer having a gross vehicle weight of 10,000 pounds or less upon the public highways of this state.

(2) This regulation is not for those arrangements used for drawing another vehicle by means of a tow truck, semitrailer with a fifth wheel type hitch, or wrecker unless coupled by ball and coupler.

(1) "Coupling" means that part of the primary connecting system normally mounted on the trailer, such as a socket, by which the connection is actually made and including the supporting attachment to the trailer frame.

(2) "Gross vehicle weight rating (GVWR)" means the value specified by the vehicle manufacturer as the loaded weight of a single vehicle.

(3) "Hitch," defined for specific uses under (a) and (b) of this subsection, means that part of the primary connecting system normally mounted on the towing vehicle, including a ball-support platform and those components which are attached to the towing vehicle.

(a) "Weight distributing hitch" means a mechanical device that connects the trailer to the towing vehicle, and by means of a leverage applied on both trailer and vehicle structures, when properly adjusted, distributes the imposed vertical load at the hitch and coupling connection between the structures of axles of towing vehicle and trailer.

(b) "Weight carrying hitch" means a mechanical and/or structural device that connects the trailer to the towing vehicle, and that does not employ features designed to redistribute the load imposed at the hitch and coupling connection.

(4) "Maximum gross trailer weight (MGTW)" means the weight of the trailer plus the weight of all cargo, consumables, and equipment loaded on the trailer when in an actual underway towing condition.

(5) "Maximum vertical load on hitch (tongue weight)" means the vertical downward static force exerted on the hitch by the coupling at the point of connection of coupling and hitch, with weight distribution features or devices, if any, deactivated. Tongue weight is measured at the trailer coupling, with the trailer on a level surface (detached from the hitch), and with trailer consumables and cargo in maximum loaded conditions.

(6) "Patrol" means Washington state patrol as defined in chapter 43.43 RCW.

(7) "Primary connecting system" means the combination of devices and their attaching structures that are normally utilized to maintain the connection between towing vehicle and trailer during towing operations. This includes, but is not limited to, the ball-and-socket type of connection or draft means. Note: This does not include a safety chain, which is part of a secondary system normally utilized only upon failure of the primary connection, nor does it include weight distributing or sway control features or devices whose function is accessory to the maintenance of the towing vehicle-trailer connection.

(8) "Safety chains" means flexible tension members connected from the front portion of the towed vehicle to the rear portion of the towing vehicle for the purpose of retaining connection between towed and towing vehicle in the event of failure of the connection provided by the primary connecting system. The term "safety chains" includes not only chains, cable, or wire ropes, or equivalent flexible member meeting the strength requirements of SAE J684 revised July 2005, but also any splice, clamp, socket, snap, eye, ring, thimble, pin, or other fastening device or forming method which is part of the assembly of any such flexible tension member.

(9) "Responsible manufacturer" means that person who manufactures a hitch or hitch component either for resale or for sale where it is not actually installed by the manufacturer.

(1) Couplings must be classified, tested, attached and labeled by the manufacturer in accordance with SAE J684 revised July 2005.

(2) Each coupling, regardless of classification or designation, must be:

(a) Equipped with a manually operated mechanism so adapted as to prevent disengagement of the unit while in operation.

(b) Designed so that the trailer can be disconnected from the towing vehicle regardless of the angle of the trailer to the towing vehicle.

(3) Each hitch ball must be equipped and installed with a lock washer or equivalent device, and each replacement hitch ball must be marketed with a lock washer or equivalent device with instructions as to proper installation provided by the responsible manufacturer.

(1) Hitches must be tested and labeled in accordance with SAE standard J684 revised July 2005 by its manufacturer to include the maximum gross trailer weight (MGTW) and the maximum vertical load on hitch (tongue weight) each is qualified to tow.

(2) The weight load carried by the hitch at its connection with the trailer coupling must not, when on a level surface, exceed the maximum tongue weight load recommended by the manufacturer for the hitch.

(1) Every towed vehicle must be coupled to the towing vehicle by means of two safety chains, cables, or wire ropes in addition to the regular drawbar, tongue, or other connection which is certified by its manufacturer as complying with SAE J684 revised July 2005.

(2) The means of attachment of safety chains must:

(a) Be located equally distant from and on opposite sides of the longitudinal centerline of the towing vehicle and of the trailer.

(b) Not be common with or utilize fasteners common with a ball or coupling.

(3) No welding operation or repair, such as cold shuts, will be performed on a safety chain subsequent to its manufacture, including the direct welding of a safety chain link to the towed or towing vehicles.

(4) Safety chains must:

(a) Be so connected that the slack for each length of chain between trailer and towing vehicle is the same and is not more than necessary to permit the proper turning of the vehicles.

(b) Be crossed in such a manner as to prevent the tongue from dropping to the ground and to maintain connection in the event of failure of the primary connecting system. See Figure 1.

(c) Be replaced immediately if they contain cut, cracked, or excessively worn links, or frayed, stranded, or otherwise defective wire rope.

(d) Not be connected to the hitch ball or to a ball mount designed to be readily removable when not in use.