OK, here is the last new one I had, and one of the last ones built. Started with a plain old brand new 1993 MDI/Yutani MD240BLC.
Step 1: Throw out the tracks, boom, etc.
Step 2: Jewell Mfg in Portland built the carrier (Cummins, Allison, Eatons) and made it the 'squirt' version- the front of the carrier hydraulically extended from off road position (about 110" WB) to highway position (about 250" WB) both for handling and bridging the weight- 80,000 lbs. (Carrier cost about $120K back then).
Step 3: Jewell puts Yutani upper on thier carrier, raises and guards cab until roofline is as close to 14' as you can get. Add catwalks, rotation hydraulics, etc.
Step 4: Jewell a builds and adds 39' logging boom, and Young 54" Grapples.
Step 5: Drive out of Jewell shop, North on I-5, at speeds up to 60 mph, no problem. I had this thing for years and drove around loading logs from here to hell and back. Was a great rig and perfect for the work we were doing.
Attached are some pics of it in action- 1st pic is at a Pacific Pride fuel stop.
I loaded thousands of loads with this rig, lol.............