Since 2017 I have worked mostly in Scotland and Scottish Natural Heritage, aka Nature.Scot require any horse powered work equipment to comply with PUWER 1998
Provision and Use Of Work Equiipment Regulations 1998, is basic Health and safety legislation affecting all work equipment. Which covers anything used at work that isn't a motor vehicle or a ship. And work includes all volunteers for a charity if that charity employs anyone, in any capacity. But check with a lawyer before you do anything.
PUWER 1998
Stop controls
Stop controls
15.—(1) Every employer shall ensure that, where appropriate, work equipment is provided with one or more readily accessible controls the operation of which will bring the work equipment to a safe condition in a safe manner.
(2) Any control required by paragraph (1) shall bring the work equipment to a complete stop where necessary for reasons of health and safety.
Emergency stop controls
16.—(1) Every employer shall ensure that, where appropriate, work equipment is provided with one or more readily accessible emergency stop controls unless it is not necessary by reason of the nature of the hazards and the time taken for the work equipment to come to a complete stop as a result of the action of any control provided by virtue of regulation 15(1).
Control systems
18.—[F1(1) Every employer shall ensure, so far as is reasonably practicable, that all control systems of work equipment—
(a)are safe; and
(b)are chosen making due allowance for the failures, faults and constraints to be expected in the planned circumstances of use.]
(2) Without prejudice to the generality of paragraph (1), a control system shall not be safe unless—
(a)its operation does not create any increased risk to health or safety;
(b)it ensures, so far as is reasonably practicable, that any fault in or damage to any part of the control system or the loss of supply of any source of energy used by the work equipment cannot result in additional or increased risk to health or safety;
(c)it does not impede the operation of any control required by regulation 15 or 16.
Isolation from sources of energy
19.—(1) Every employer shall ensure that where appropriate work equipment is provided with suitable means to isolate it from all its sources of energy.
(2) Without prejudice to the generality of paragraph (1), the means mentioned in that paragraph shall not be suitable unless they are clearly identifiable and readily accessible.
(3) Every employer shall take appropriate measures to ensure that re-connection of any energy source to work equipment does not expose any person using the work equipment to any risk to his health or safety.
There is one consistenmt theme in PUWER 1998. Runaway equipment is not good. And if youy have to risk your neck to stop it that isn't good either.
This why Runaways aren't funny.
Obamobilty runs three systems.
Manual.
There is a ripcord and panic buttons which break the electrical circuit keeping the pony attached.
Remote.
there is a push button remote which electronically releases the pony at up to about 20 mteres. This is NOT Failsafe.
Automatic.
This is a radio linked system telling the vehicle to STAY connected to the pony if the dsitance betweem the operator and the vehiocle is less than 10 metres. If the pony bolts, it gets 10 metres before the pony is automatically released. Any faults in the system release the pony.