Steel Rim Bracing

[Farrell]

I serviced a Wissner 5' four-or-so small grand today. Nice worn out old piano. It had a nice heavy laminated rim and several good size wood braces underneath. All the wood braces were on the treble side to the middle (I think there were three). On the bass side there was a triangle shaped 1/4" plate steel brace that went from about where the bass break would be on the belly rail, to the mid point of the straight side to the middle wooden brace and back.

I wonder why a steel triangle brace rather than just a long wooden beam and perhaps and cross piece to the long side? Thoughts?

Terry Farrell