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A large ballast tractor pulling a load using a drawbar

General duty tow hitch from VBG on a truck and a drawbar on a trailer, showing a connected drawbar eye

Rockinger drawbar coupling, in which the drawbar eye gets locked

A drawbar is a solid coupling between a hauling vehicle and its hauled load. Drawbars are in common use with rail transport; road trailers, both large and small, industrial and recreational; and agricultural equipment.

Agriculture and horse-drawn vehicles

Agricultural equipment is hauled by a tractor-mounted drawbar. Specialist agricultural tools such as ploughs are attached to specialist drawbars which have functions in addition to transmitting tractive force. This was partly made redundant with Ferguson's development of the three-point linkage in his famous TE20. A wooden drawbar extends from the front of a wagon, cart, chariot or other horse-drawn vehicles to between the horses. A steel drawbar attaches a three-point hitch or other farm implement to a tractor.

Road

A drawbar is a towing or pushing connection between a tractive vehicle and its load.

Light vehicles

On light vehicles, the most common coupling is an A-frame drawbar coupled to a 1 7/8 inch or 50 mm tow ball. These drawbars transmit around 10% of the gross trailer weight through the coupling.

Heavy vehicles

The direction of haulage may be push or pull, though pushing tends to be for a pair of ballast tractors working together, one pulling and the other pushing an exceptional load on a specialist trailer. The most common drawbar configuration for heavy vehicles is an A-frame drawbar at the front of a full trailer that connects to a tow coupling on a hauling vehicle^[1]

On heavy vehicles, the drawbar is coupled using a drawbar eye, typically of 40 mm or 50 mm diameter, connected to a bolt and pin coupling. Commonly seen brands include Ringfeder, V. Orlandi and Jost Rockinger. These drawbars transmit little or no downwards force through the coupling.

The drawbar should not be confused with the fifth wheel coupling. The drawbar requires a trailer which either loads the drawbar lightly (for example a small boat trailer, or caravan, or the load is the weight of the coupling components only (larger trailers, usually but not always with a steerable hauled axle, front or rear). By contrast, the fifth wheel is designed to transmit a proportion of the load's weight to the hauling vehicle. Drawbar configuration is mostly seen on hydraulic modular trailer and ballast tractor combination to haul oversize loads which require special trailer and tractor.

Drawbar eye

A drawbar eye, also called tow eye, is a mechanical part to connect an independent trailer/dolly via a drawbar coupling to a tractor.^[2] the eye is connected to the front end of a drawbar with bolt, flange-mounting or welding.^[3] Most are made from high tension material to bear heavy loads while being pulled by the tractor. The eye is made in the shape of an "i" with a hole at top which is locked in the drawbar coupling and the lower part is mounted to the drawbar making it an essential connector between the drawbar and drawbar coupling. The drawbar eye is used in many heavy transport operations around the world. It is mostly used for agriculture equipment, construction equipment, road trains, dolly trailers, full trailer and hydraulic modular trailers.

Rail

Two or more passenger or freight cars may be attached by means of a drawbar rather than a coupler. At each end of the permanently coupled vehicles there is a regular coupler, such as the North American Janney coupler or the Russian SA3 coupler. The use of a drawbar eliminates slack action.

Rail applications

References

^ "What is a drawbar trailer". 19 July 2021.
^ "Drawbar Eye Definition". Law Insider. Retrieved 2022-03-14.
^ "Drawbar eyes". VBG. Retrieved 2022-03-14.

External links

US 6739402 Transport drawbar
US 5096075 Slackless drawbar assembly with gravity responsive wedge (rail application)
US 5598937 Slackless drawbar assembly (rail application)

[1] "What is a drawbar trailer". 19 July 2021.

[2] "Drawbar Eye Definition". Law Insider. Retrieved 2022-03-14.

[3] "Drawbar eyes". VBG. Retrieved 2022-03-14.

[1]

[2]

[3]

@@ Line 1: / Line 1: @@
+{{Short description|Vehicle and trailer coupling}}
 {{about|haulage||Drawbar (disambiguation)}}
-{{no footnotes|date=January 2015}}
+{{more footnotes needed|date=January 2015}}
 {{Wiktionary|drawbar}}
 [[File:Rawcliffe Ballast Tractor & Trannsformer.jpg|thumb|right|A large [[ballast tractor]] pulling a load using a drawbar]]
-[[Image:Drawbar trailer coupling.jpg|thumb|General duty [[tow hitch]] from VBG on a truck and a drawbar on a trailer]]
+[[Image:Drawbar trailer coupling.jpg|thumb|General duty [[tow hitch]] from VBG on a truck and a drawbar on a trailer, showing a connected drawbar eye]]
+[[File:Rockinger Anhängerkupplung.jpg|thumb|[[:de:Rockinger|Rockinger]] drawbar coupling, in which the drawbar eye gets locked]]
-A '''drawbar''' is a solid [[coupling]] between a [[hauling]] vehicle and its hauled load.  Drawbars are in common use with rail transport, road trailers, both large and small, industrial and recreational, and with agricultural equipment.
+A '''drawbar''' is a solid [[coupling]] between a [[hauling]] vehicle and its hauled load.  Drawbars are in common use with rail transport; road trailers, both large and small, industrial and recreational; and agricultural equipment.
 == Agriculture and horse-drawn vehicles ==
+[[Agricultural machinery|Agricultural equipment]] is hauled by a tractor-mounted drawbar. Specialist agricultural tools such as [[plough]]s are attached to specialist drawbars which have functions in addition to transmitting tractive force. This was partly made redundant with [[Harry Ferguson|Ferguson]]'s development of the three-point linkage in his famous [[Ferguson TE20|TE20]].
-{{Expand section|date=November 2008}}
+A wooden drawbar extends from the front of a [[wagon]], [[cart]], [[chariot]] or other [[horse-drawn vehicle]]s to between the [[horse]]s. A steel drawbar attaches a [[three-point hitch]] or other [[farm implement]] to a [[tractor]].
-[[Agricultural machinery|Agricultural equipment]] is hauled by a tractor mounted drawbar.  Specialist agricultural tools such as [[plough]]s are attached to specialist drawbars which have functions in addition to transmitting tractive force. This was partly made redundant with Ferguson’s development of the 3 point linkage in his famous TE20.
-A wooden ''drawbar'' extends from the front of a [[wagon]], [[cart]], [[chariot]] or other [[horse-drawn vehicle]]s to between the [[horse]]s. A steel ''drawbar'' attaches a [[three-point hitch]] or other [[farm implement]] to a [[tractor]].
 ==Road==
+A drawbar is a towing or pushing connection between a tractive vehicle and its load.
-A drawbar is mounted or located on the tractive vehicle and is used to accept the coupling of the load.  The direction of haulage may be push or pull, though pushing tends to be for a pair of [[ballast tractor]]s working one pulling and the other pushing an exceptional load on a specialist trailer.
+===Light vehicles===
-The drawbar should not be confused with the [[fifth wheel coupling]].  The drawbar requires a [[Trailer (vehicle)|trailer]] which either loads the drawbar lightly (for example a small [[boat trailer]], or [[Caravan (towed trailer)|caravan]], where a load of up to ~{{convert|50|kg|lb|abbr=on}} is part of correct trailer loading practice), or the load is the weight of the coupling components only (larger trailers, usually but not always with a steerable hauled axle, front or rear).  By contrast, the fifth wheel is designed to transmit a major proportion of the load's weight to the hauling vehicle.
+On light vehicles, the most common coupling is an A-frame drawbar coupled to a 1 7/8 inch or 50&nbsp;mm tow ball. These drawbars transmit around 10% of the gross trailer weight through the coupling.
+===Heavy vehicles===
+The direction of haulage may be push or pull, though pushing tends to be for a pair of [[ballast tractor]]s working together, one pulling and the other pushing an exceptional load on a specialist trailer. The most common drawbar configuration for heavy vehicles is an A-frame drawbar at the front of a [[Trailer (vehicle)#Full trailer|full trailer]] that connects to a tow coupling on a hauling vehicle<ref>{{cite web|url=https://mocktheorytest.com/resources/what-is-a-drawbar-trailer/|title=What is a drawbar trailer|date=19 July 2021}}</ref>
+On heavy vehicles, the drawbar is coupled using a [[drawbar eye]], typically of 40&nbsp;mm or 50&nbsp;mm diameter, connected to a bolt and pin coupling. Commonly seen brands include [[Ringfeder]], V. Orlandi and [[:de:Jost Werke|Jost]] ''[[:de:Rockinger|Rockinger]]''. These drawbars transmit little or no downwards force through the coupling.
+The drawbar should not be confused with the [[fifth wheel coupling]].  The drawbar requires a [[Trailer (vehicle)|trailer]] which either loads the drawbar lightly (for example a small [[boat trailer]], or [[Caravan (towed trailer)|caravan]], or the load is the weight of the coupling components only (larger trailers, usually but not always with a steerable hauled axle, front or rear). By contrast, the fifth wheel is designed to transmit a proportion of the load's weight to the hauling vehicle. Drawbar configuration is mostly seen on [[hydraulic modular trailer]] and [[ballast tractor]] combination to haul [[oversize load]]s which require special trailer and tractor.
+===Drawbar eye===
+A drawbar eye, also called tow eye, is a mechanical part to connect an independent [[Trailer (vehicle)|trailer]]/[[Dolly (trailer)|dolly]] via a drawbar coupling to a [[Ballast tractor|tractor]].<ref>{{Cite web |title=Drawbar Eye Definition |url=https://www.lawinsider.com/dictionary/drawbar-eye |access-date=2022-03-14 |website=Law Insider |language=en}}</ref> the eye is connected to the front end of a drawbar with bolt, flange-mounting or welding.<ref>{{Cite web |title=Drawbar eyes |url=https://www.vbg.eu/en/products/drawbar-eyes/ |access-date=2022-03-14 |website=VBG |language=en}}</ref> Most are made from high tension material to bear heavy loads while being pulled by the tractor. The eye is made in the shape of an "i" with a hole at top which is locked in the drawbar coupling and the lower part is mounted to the drawbar making it an essential connector between the drawbar and drawbar coupling. The drawbar eye is used in many heavy transport operations around the world. It is mostly used for [[agriculture]] equipment, [[construction]] equipment, [[road train]]s, [[Dolly (trailer)|dolly trailers]], [[Full-trailer|full trailer]] and [[Hydraulic modular trailer|hydraulic modular trailers]].
 ==Rail==
 {{train topics}}
 {{Expand section|date=September 2017}}
-Two or more [[Passenger car (rail)|passenger cars]] or [[freight car]]s may be attached by means of a drawbar. At both extremes there is a regular [[Railway coupling|coupler]] such as the North American [[Janney coupler]] or the Russian [[SA3 coupler]]. This drawbar eliminates [[slack action]].
+Two or more [[Passenger car (rail)|passenger]] or [[freight car]]s may be attached by means of a drawbar rather than a [[railway coupling|coupler]]. At each end of the permanently coupled vehicles there is a regular coupler, such as the North American [[Janney coupler]] or the Russian [[SA3 coupler]]. The use of a drawbar eliminates [[slack action]].
-=== Rail applications === <!-- There are others -->
+=== Rail applications ===
 * [[MR-90]]
 * [[MR-63]]
@@ Line 28: / Line 39: @@
 * [[MPM-10]]
 * [[Drawgear]]
+<!-- There are others. -->
-{{Railway coupling}}
 == See also ==
-{{div col|colwidth=30em}}
+{{div col|colwidth=23em}}
+* [[Ballast tractor]]
 * [[Drawbar force gauge]]
 * [[Drawgear]]
@@ Line 44: / Line 55: @@
 ==References==
+{{reflist}}
-<references/>
+== External links ==
 {{refbegin}}
 * {{patent|US|6739402|Transport drawbar}}
@@ Line 50: / Line 63: @@
 * {{patent|US|5598937|Slackless drawbar assembly (rail application)}}
 {{refend}}
+{{Railway coupling}}
 [[Category:Agricultural machinery]]
@@ Line 56: / Line 70: @@
 [[Category:Transport operations]]
 [[Category:Articulated vehicles]]
+[[Category:Heavy equipment]]

v t e Railway coupling
General	Railway coupling by country Railway coupling conversion
Systems	Buffers and chain Janney / AAR coupler Type F & H : Tightlock coupling SA3 coupler C-AKv coupler Unicoupler/Intermat Scharfenberg coupler Norwegian coupling Dual coupling Drawbar Draft gear
Categories	Couplers