Sheet N-302-EN: Which tray lands the trunks on the CVS and SPA/SPB cabinets, and how the fan-wall front zone is shared

What this sheet shows

N-302-EN is the central-spine detail, drawn at 1:75. The line under the top border names the zone and the two views: Central spine zone (OOB-A, CVS-A, SPA-1..3, SPB-1..3, CVS-B, OOB-B): plan (upper) and X–Z elevation (lower). Fibre drops from the trays onto the cabinet tops. Dimensions in mm. The plan puts fan walls FW-04, FW-05 and FW-06 along the upper side, each marked fan wall 3000×1400 and (facility context), with a hatched front zone 1050 shared use in front of each. Under the walls the cabinet row is R042, NETB-CU07, OOB-A, CVS-A, SPA-1, SPA-2 and SPA-3, then a gap, then SPB-1, SPB-2, SPB-3, CVS-B, OOB-B, NETA-CU08 and R043. Dashed lines are labeled TA on the fan-wall side of the cabinets, TL along the row and TB on the side with the dotted band. The lower view is the X–Z elevation of the same run, and that view labels R044 past R043. The graphic scale under the elevation reads 0 to 2 m and is marked 1:75. The detail is part of the GPU hall reference.

Trunks landing in the central cabinets

The table at the upper right is titled Trunks landing in central cabinets, with columns Cabinet, Tray and Trunks. CVS-A (listed CS-A) is on TA with 60 trunks, and CVS-B (listed CS-B) is on TB with 60 trunks. SPA-1, SPA-2 and SPA-3 are each on TA with 120 trunks. SPB-1, SPB-2 and SPB-3 are each on TB with 120 trunks. On the plan, TA is the dashed line on the fan-wall side of the row and TB is the dashed line on the side with the dotted band, so the CVS-A and SPA rows use the fan-wall-side tray and the CVS-B and SPB rows use the far-side tray. The header's zone is OOB-A, CVS-A, SPA-1..3, SPB-1..3, CVS-B, OOB-B. OOB-A and OOB-B are on that list and on the plan, and neither is a row in this table. Note 1 fixes the unit behind every count in the table: 1 trunk = 18 × MPO-12 legs / 216 fibres, and it points that definition to N-503-EN.

Drops, elevations and the shared front zone

Note 2 separates the two drops onto the cabinet top. Jumpers come from TL, bottom Z3550. Trunks come from TA/TB, bottom Z3900, and enter at the cabinet top rear. Bend radius is at least 130 mm for 13 mm trunks. The elevation draws TA and TB as one band because the caption says TA (/) and TB (\) both run bottom Z3900–top Z4100 and coincide in X–Z projection, with Y positions on the plan and on the sections. TL is the lower band, labeled bottom Z3550, top Z3650. The elevation dimensions 128 from the cabinet-top line Z3422 up to the TL bottom, and 478 from that line up to the TA/TB bottom at Z3900. Note 3 gives the cabinet: height 2294 mm on rails at Z1128, cabinet top Z3422. The elevation dimensions 98 from floor-board top Z1030 up to the cabinet base and labels the body cabinet 2294. The printed figures meet: Z1030 plus 98 is Z1128, and Z1128 plus 2294 is Z3422. Z3422 plus 128 is the TL bottom Z3550, and Z3422 plus 478 is the TA/TB bottom Z3900. Note 4 names the front zone. Fan walls FW-04, FW-05 and FW-06 face OOB-A, SPA-3/SPB-1 and OOB-B. The note gives a 1,050 mm front zone shared in time between switch withdrawal (1,000) and fan-wall service (850). The plan prints that zone on each wall as front zone 1050 shared use.

Status

The title block dates the sheet 2026-10-05 and issues it as Public Edition P2, number N-302-EN, sheet 14 of 30, scale 1:75, units mm. The sheet title is Central spine zone detail: plan and X–Z elevation. The status line reads: reference design for study and evaluation — not for construction. Note 1 points the trunk unit, 18 × MPO-12 legs / 216 fibres, to N-503-EN. Notes 2 and 3 state the drop elevations and the 2294 mm cabinet on rails at Z1128, with cabinet top Z3422. Note 4 states the 1,050 mm front zone shared in time between switch withdrawal (1,000) and fan-wall service (850). The drawing is part of the Public Edition P2 network reference design.

Sheet guide — the devices on this drawing

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