Model D11 R&M Spacemaster I - 25 to 30 ton Basemounted- Maintenance Instructions and Spare Parts. PDF. Model D11 R&M Spacemaster I - 25 to 30 ton Double Girder- Maintenance Instructions and Spare Parts. PDF. Model D11 R&M Spacemaster I - 7.5 to 10 ton Monorail - Maintenance Instructions and Spare Parts. PDF.