Force required to lift a hatch

[kewsky]

I plan to build a hatch door in one side of my shed. The plan is that the hatch door will be hinged at the top long edge. The hatch door will open from the bottom long edge. The hatch door will open out and up to a horizontal position (possibly slightly past horizontal). My question is what lifting force will be required to lift the door, what force will be required to keep the door in the open position, what forces (value and direction) will be exerted on the hinge during lifting and open. Sizes have not been decided yet so assume door size; horizontal length = L, vertical height = H, weight of door =W. Gravity here is normal. Any help, advice or insight would be appreciated.

 

[kewsky]

An additional thought. Could a counterweight be added to aid lifting without building outside the shed?

 

[sophiecentaur]

The counterweight can either be on a lever or on a pulley, pulling up the hatch. There are also airstruts (as on car hatchback doors) available.
The formula for the force, if the door starts hanging vertical, will, of course, where the handle is. If the handle is half way up the door, the force will be almost zero at the start and go to the value of the door weight when it's horizontal (if you are pulling it vertically) then it gets less when lifting further.
I think you will need to produce a diagram giving some idea of where and how the force will be applied to the door. Direction and point of application will have a huge effect on the actual force you need
I am not sure what you want do do but you might find https://www.sgs-engineering.com/help-advice/how-to-calculate-the-force-required-for-a-gas-strut/ helpful if you want to make the job easy for a person who's not too strong, even if the door is heavy.

 

[berkeman]

The plan is that the hatch door will be hinged at the top long edge. The hatch door will open from the bottom long edge. The hatch door will open out and up to a horizontal position (possibly slightly past horizontal).

Sorry to be Captain Obvious here, but why not just use a conventional door with side hinges? Is there some need for the hatch door to end up horizontal and high up?

What kinds of things pass through the open hatch? Just people and animals, or small equipment, or car-size vehicles, etc?

 

[sophiecentaur]

What kinds of things pass through the open hatch?

Who let the dogs out?