This is a half section of my present gantry hoist track splice design. C is
the 4" channel, V the 3/8" thick central splice plate between the channels,
H the 3/8" thick horizontal splice plate under the tension flanges and A the
angle iron splice above the compression flanges.

My question is how to weld the inverted T joint between V and H. I think an
inside fillet weld will deform H upward and require grinding off the sharp
and square lower corners of the channel. Is a row of plug or slot welds in H
a reasonable alternative to avoid distortion and interference?

The 6" high vertical center plate V alone has nearly the same Ixx as the two
channels so I don't think welding it to H is essential but connecting them
should make the joint stiffer and one-man assembly easier. The angle A on
top bolts to V and C afterwards, and gives the central hanger shackle pin
more bearing area than V alone would.

VA
VA
VA
VAAAAAA
VCCCCCC
VC
VC
VC
VC
VC
VCCCCCC
HHHHHH