$1\mathrm{.}53$ In the steel structure shown, a $6-$mm$-$diameter pin is used at $C$ and $10-$mm$-$diameter pins are used at $B$ and $D.$ The ultimate shearing stress is $150$MPa at all connections, and the ultimate normal stress is $400$MPa in link $BD.$ Knowing that a factor of safety of $3\mathrm{.}0$ is desired, determine the largest load $P$ that can be applied at $A.$ Note that link $BD$ is not reinforced around the pin holes.

Side view