Well, according to common engineering formulas, three supports inline will never get a third of the load each. It is a continuous beam with a distributed load

Well, according to common engineering formulas, three supports inline will never get a third of the load each. It is a continuous beam with a distributed load (only own weight). Look for "Continuous Beam – Two Equal Spans – Uniformly Distributed Load" here: https://www.linsgroup.com/MECHANICAL_DESIGN/Beam/beam_formula.htm https://www.linsgroup.com/MECHANICAL_DESIGN/Beam/beam_formul... Hint: you'd better put the strongest guy in the middle.