What forces are relevant when it comes to a davit lifting arm with a support. I'm not sure how to take the weight of the davit into account and also how to calculate the max stress/strain on the system. The davit is set on a beam and it lifts a 979 lb lid off of a tank. There is a support coming from the vertical piece about 3/4's of the way up that reaches over to the horizontal piece about 1/2 way.

What forces are relevant when it comes to a davit lifting arm with a support? I'm not sure how to take the weight of the davit into account or how to calculate the max stress/strain on the system. 

The davit is set on a beam and it lifts a 979 lb lid off of a tank. There is a support coming from the vertical piece about three-fourths of the way up that reaches over to the horizontal piece about half way.