Помогите правильно перевести предложение. He tried to solve by himself and with his own resources a series of…

He tried to solve by himself and with his own resources a series of problems with in the end required the united efforts of two generations of engineers. — Он пытался разрешить сам, своими собственными силами, серию задач, но в итоге понадобились усилия двух поколений инженеров.