It will be an odd design that is neither self breaking (so lowly geared that the maximum design load does not spin the motor) - smaller winch designs are like this, nor does any kind of brake come on under spring pressure if there is a power loss. Unless the loads are so small that no injury could ensue, the brake release circuit needs to be interlocked to the motor power - so if there is no power- the brakes go and stay on, I'm surprised it is not like that.

Where in the world are you ? I ask because in the EU that would be a failure to meet machinery directive.

Mike

PS

consider this extract from

EN 15011:2011 (E)

5.4.2 Braking systems
5.4.2.1 General
All power driven motions shall be under the control of a braking system at all times. The braking systems shall be such that movements can be decelerated, the motions can be held and unintentional movements avoided.
The systems shall be capable of bringing a fully loaded crane to rest from the highest speed it can attain.
5.4.2.2 Mechanical service brakes in power driven motions
Only power released brakes shall be used and they shall maintain their ability to stop the motion, at all times. Brakes shall be protected from the ingress of substances within the environment, which are likely to have a detrimental effect on the performance of the brake.
NOTE Where electrical braking systems are used, the associated mechanical brake is only subjected to limited use. Special attention therefore may be neede d to maintain the required mechanical braking torque, see 7.3.3.
Mechanical service brakes shall engage automatically in the following cases:
the control device returns to its neutral position;
the power supply to the brake is interrupted;
the emergency stop device is activated

etc.

It will be an odd design that is neither self breaking (so lowly geared that the maximum design load does not spin the motor) - smaller winch designs are like this, nor does any kind of brake come on under spring pressure if there is a power loss. Unless the loads are so small that no injury could ensue, the brake release circuit needs to be interlocked to the motor power - so if there is no power- the brakes go and stay on, I'm surprised it is not like that.

Where in the world are you ? I ask because in the EU that would be a failure to meet machinery directive.

Mike

PS

consider this extract from

EN 15011:2011 (E)

5.4.2 Braking systems
5.4.2.1 General
All power driven motions shall be under the control of a braking system at all times. The braking systems shall be such that movements can be decelerated, the motions can be held and unintentional movements avoided.
The systems shall be capable of bringing a fully loaded crane to rest from the highest speed it can attain.
5.4.2.2 Mechanical service brakes in power driven motions
Only power released brakes shall be used and they shall maintain their ability to stop the motion, at all times. Brakes shall be protected from the ingress of substances within the environment, which are likely to have a detrimental effect on the performance of the brake.
NOTE Where electrical braking systems are used, the associated mechanical brake is only subjected to limited use. Special attention therefore may be neede d to maintain the required mechanical braking torque, see 7.3.3.
Mechanical service brakes shall engage automatically in the following cases:
the control device returns to its neutral position;
the power supply to the brake is interrupted;
the emergency stop device is activated

etc.

Thanks Mike for the response and extracts from EN 15011:2011 (E), I will read more on the subject. 

The Issue of geographical location, however, doesn't really matter because machines anywhere in the world still fail with all the required protection systems in place, that's why we re-engineer, redesign and maintain systems based on our daily experiences and changes in technology, standards and statutes. 

Region  can  matter though - US regulation of cranes through OSHA is lot less prescriptive in this regard, and machines coming to Europe from the US that only meet the US rules have to be modified with additional safety features before they may be used here I'm not sure if that includes power failure emergency braking because by they get here, they certainly have it.

I know more detail about a similar problem with things like IR curtains on metal cutting machines that get added to imported models to detect if a hand is about to be put into the moving cutters - not needed over there apparently so not fitted.

It would be quite nice if the standards were indeed the same, but they are very much not.

(and at least one US maker knows it.. they seem to be advocating a tightening of the US rules  and in the mean time suggesting that discerning US customers should request the EU compliant model - which is interesting)

I am not sure about other parts of the world, I suspect that there are places laxer still in the far east.

Mike.