IMO 3: Maintaining a set walking speed down a staircase

1. Definition

One person on a stair 2 m wide and 10 m long, measured along the incline, walks downward at a set speed of 1 m/s. The paragraph repeats the wording of Test 2.

Source: IMO MSC.1/Circ.1533, Annex 3, Appendix 2, Test 3, para. 5, p. 9. This is a paraphrase, not the text of the standard.

Reference: International Maritime Organization (2016). Revised guidelines on evacuation analysis for new and existing passenger ships. MSC.1/Circ.1533, 6 June 2016. https://edocs.imo.org/Final%20Documents/English/MSC.1-CIRC.1533%20(E).docx (Page numbers are the printed page numbers of Annex 3 (“Annex 3, page n”). Tests are cited by test number and paragraph of Appendix 2.)

2. Scenario

Scenario picture not available.

3. What to expect

The person covers the 10 m in 10 s. IMO gives no tolerance. The paragraph does not say how the set speed relates to the stair speeds of Table 3.5 (Annex 3, p. 6).

Our criterion: 1 m/s on a 10 m stair (along the incline) gives 10 s (+/- 0.5 s)

The stair is a flat speed-factor zone; the desired speed is set so that v0 * factor = 1 m/s. Up and down use the same mechanism, so direction is not modelled.

4. Our result

Status: PASS

Test cases of this row

5. Our implementation

Deviations from the standard:

• The stair is a flat polygon (10.4 m by 2 m) covered by one speed-factor zone with factor 0.75. It has no incline, no steps and no direction. The test uses the same mechanism as Test 2 with a different constant, so it does not distinguish down from up.
• The desired speed is set to 1/0.75 m/s, so that desired speed times zone factor equals 1 m/s (decision D14). The test checks that the zone factor is applied, not that the model reproduces a stair speed from Table 3.5.
• The agent starts in a 0.3 m by 0.4 m patch at the left end, and the exit is a strip 0.2 m deep and 0.4 m wide at the right end, so the walked distance is about 10 m in plan view.
• The pass rule is the suite’s own: the evacuation time lies between 9.5 s and 10.5 s (10 s +/- 0.5 s).
• The scenario is built in code (tests/vv/test_imo.py); one seed (42).

Model: CollisionFreeSpeedModel

• Test function: tests/vv/test_imo.py::test_travel_time

6. Our notebook

No notebook for this test yet.