IBM J15 Manual page 51

Figure 13. Screw locations to attach the inner rail to the enclosure
5. Install the inner section of the rail onto each side of the disk enclosure, as shown in Figure 14 on page
23.
Figure 14. Attaching the inner rail section to the enclosure
6. Use the M5 screws to install the outer rail member and bracket assembly to the rack, as shown in
Figure 15 on page 23.
Figure 15. Installing the rail assembly to the rack frame
For example, Figure 16 on page 23 shows the front of the rail that is attached to the frame.
Figure 16. Example of the required rack space
7. Repeat steps "5" on page 23 through "6" on page 23 to install the opposite rail.
Chapter 2. Installing the system hardware 23