Handhole schedule from the 3D duct bank model, Silver Subdivision

All 48 handholes, pull boxes and manholes in the signal and communications duct bank model are in an Excel schedule with type, size and depth. Depth is top of cover minus the bottom of the structure in the 3D model. For type HH-3 the depth in the Item Type data does not match the model, and two vaults at SR-305 have no Item Type data.

MicroStation DGN, plan and 3D duct bank modelsSilver Subdivision, MP 702.30–703.36, Silver Bend, UTUtah Central Zone, NAD83(2011), US survey feet; NAVD 88Prepared Nov 5, 2026

Summary

Depth check · Type HH-3

HH-3 is 48 in deep in the model but 36 in in the Item Type data

All 6 HH-3 splice handholes are 12 in deeper in the 3D model than their Depth property says. Sheet 3 of SC-401_Handhole_and_Pull_Box_Details.pdf shows 48 in, so the error is in the Item Type data on the HH-3 cell, not in the model.

Action: correct Depth on the HH-3 cell in the cell library and rerun the schedule.

Plan vs. 3D · SR-305

2 vaults at SR-305 exist only in the 3D model

MH-141 and MH-142 on either side of SR-305, at Sta. 146+10 and Sta. 147+10, are modeled as solids in the 3D Duct Bank model but have no cell in the Plan model and so no Item Type data. Type MH-4 and 48 × 72 in were read from the geometry.

Action: place the cells in the plan and have the designer confirm the type.

MH-4 is rated AASHTO H-20. If either vault sits in the travel lanes of SR-305, UDOT’s requirements govern the load rating; confirm with UDOT through the utility permit.

Schedule

48 structures scheduled, 40 without exceptions

The schedule lists type, size, station, milepost, offset, coordinates, cover and bottom elevations and depth for all 48 structures. For PB-1, HH-2 and MH-4 the Item Type depth matches the model to the inch.

Model and schedule

Silver Subdivision, MP 702.30–703.36: duct bank along the main track, a crossing under the main track and siding at Sta. 126+25 to the signal bungalow at CP Silver Bend, and a crossing under SR-305. Turn the model and click a structure for type, size and depth. The schedule follows the selection.

Drag to turn · right-drag to pan · scroll to zoom

Overview · MP 702.30–703.36Click to jump to the nearest structure

Structure types

Depth by type per detail sheet SC-401, the Item Type data and the 3D model.

Deliverable

SilverSub_Handhole_Schedule_MP702-704.xlsx

  • Schedule48 rows, 15 columns
  • Exceptions8 rows
  • Types4 rows

Columns in Schedule: Structure ID, Type, Size, Station, MP, Offset, Northing, Easting, Cover El., Bottom El., Depth (Model), Depth (Item Type), Difference, Load Rating, Remarks.

Schedule

Sources and method

Sources

  • SilverSub_SC_DuctBank_MP702-704.dgnMicroStation DGN V8 with Plan (2D) and 3D Duct Bank models; structure cells PB-1, HH-2, HH-3 and MH-4 with Item Type data43.2 MB
  • SC-401_Handhole_and_Pull_Box_Details.pdfStandard details: inside dimensions, depth and load rating by structure type4 sheets
  • SilverSub_Signal_Comm_Underground_Specs.pdfProject specifications for conduit, handholes and pull boxes; depth is measured from top of cover to the floor22 pages

Method

  1. 46 structure cells (PB-1, HH-2, HH-3, MH-4) were read from the Plan model with their Item Type properties: Structure ID, Type, Size and Depth.
  2. 48 structure solids were read from the 3D Duct Bank model. Each solid was matched to a cell by plan position (within 0.3 ft). Two solids had no cell.
  3. Depth was taken as top of cover minus the inside bottom of the structure in the 3D model and compared with the Depth property and with detail sheet SC-401.
  4. Station, milepost and offset were computed from the main track centerline in the same DGN, with Sta. 100+00 at MP 702.30. Coordinates and elevations are as stored in the file: Utah Central Zone (FIPS 4302), NAD83(2011), US survey feet, and NAVD 88.
  5. The schedule was written to Excel with a separate Exceptions sheet.

Assumptions and limitations

  • Differences of more than 1 in between the model and the Item Type data are flagged.
  • Type and size for MH-141 and MH-142 come from the solids, since they have no Item Type data.
  • Bottom is the inside floor of the structure. Extensions and cover thickness are included in the depth as modeled.
  • Positions and elevations are used as modeled. They have not been compared with an as-built survey.
  • MH-4 vaults are taken as AASHTO H-20. Whether MH-141 and MH-142 sit in the travel lanes or the shoulder of SR-305 has not been checked, and UDOT’s requirements govern the load rating there. Confirm with UDOT through the utility permit before the vaults are ordered.