ID (KPI identifier)

M

Equivalent Moves Per Hour (EMPH)

GRAMMAR

KPI name

M

Equivalent Moves Per Hour

GRAMMAR

KPI type

M

OperationalPerformance

GRAMMAR

Applicable to

Crane, Terminal, CraneOperations, STS Cranes

Also known as

O

TIC Description

Definition

M

Equivalent Moves Per Hour (EMPH) measures a Ship-to-Shore (STS) quay crane's operational productivity adjusted for crane size, expressed as equivalent moves per hour on a standard reference crane.

TIC Description

Further Detail

O

1. Context and rationale

Industry practice uses GMPH and NMPH to assess crane productivity. However, a crane with 65 m outreach and a crane with 48 m outreach reporting the same NMPH are not performing equally — the larger crane moves its spreader through significantly more space per cycle. Without size normalization, cross-terminal benchmarking does not account for differences in crane size.

EMPH exists to answer one question that no current KPI addresses: How well is this crane performing relative to its physical size?

2. Measurement Definitions

All measurements shall be taken from the crane's design drawings or specification sheet. The following definitions apply:

• Outreach (O): The horizontal distance from the centreline of the waterside rail to the waterside spreader position centreline when the trolley is at end-limit-stop, measured in meters.

• Rail span (S): The horizontal distance between the centreline of the waterside rail and the centreline of the landside rail, measured in meters. Also known as mid span.

• Backreach (B): The horizontal distance from the centreline of the landside rail to the landside spreader position centreline when the trolley is at end-limit-stop, measured in meters. This aligns with standard OEM specification convention.

• Max hoist height (H): The vertical distance from the top of the waterside rail to the underside of the spreader when the hoist is at upper-end-limit-stop, measured in meters.

• Portal: The area between the waterside and landside legs of the crane. Some terminals use this area for container set-down (RPL-P configuration), while others use it for hatch cover storage and set containers in the backreach (RPL-B configuration).

3. Reference Path Length (RPL) - Two Configurations

The crane's working envelope is characterized by its Reference Path Length (RPL): the total distance the spreader travels in one standardized reference cycle. Two RPL variants account for the two primary terminal configurations.

RPL-P (Portal drop):

Container is set down between the crane legs (portal centerline, also known as mid span). The trolley travels from the seaside pick position at 80% of outreach, across the waterside rail, to the portal centerline at half the rail span. The cycle includes the outbound and return trolley trip, plus four hoist motions: hoist loaded, lower loaded, hoist empty, and lower empty.

• Trolley distance (one way) = 0.8 × O + 0.5 × S

• Hoist travel (one way) = 0.8 × H

• RPL-P = 2 × (0.8 × O + 0.5 × S) + 4 × (0.8 × H)
  
  

RPL-B (Backreach drop):

Container is set down on the landside of the crane, beyond the legs. The trolley travels from the seaside pick position at 80% of outreach, across the waterside rail, across the full rail span, past the landside rail, and out to the designated landside container exchange point. Some terminals use this configuration because the portal area is used for hatch cover storage.

• Trolley distance (one way) = 0.8 × O + S + B

• Hoist travel (one way) = 0.8 × H

• RPL-B = 2 × (0.8 × O + S + B) + 4 × (0.8 × H)

Reference crane dimensions:

• Reference outreach (O): 55 m

• Reference rail span (S): 30 m

• Reference max hoist height (H): 46 m

• Reference backreach (B): 15 m

Reference RPL-P = 2 × (0.8 × 55 + 0.5 × 30) + 4 × (0.8 × 46) = 2 × (44 + 15) + 4 × 36.8 = 118.0 + 147.2 = 265.2 m

Reference RPL-B = 2 × (0.8 × 55 + 30 + 15) + 4 × (0.8 × 46) = 2 × (44 + 30 + 15) + 4 × 36.8 = 178.0 + 147.2 = 325.2 m

RPL values may also be used independently as a standardized crane size descriptor for comparing STS cranes across fleets.

Terminals shall use RPL-P or RPL-B consistently based on their operational configuration. When reporting EMPH, the RPL type used shall be stated.

4. EMPH Calculation

EMPH converts observed NMPH into equivalent moves per hour on the reference crane:

• EMPH = NMPH × (RPL_crane / RPL_ref)

The ratio RPL_crane / RPL_ref is a size adjustment factor. If the crane is larger than the reference, the ratio is greater than 1 and the crane receives a modest credit because its spreader covers more distance per cycle. If the crane is smaller, the ratio is less than 1, reflecting that each move involves less physical work.

The output remains in moves per hour, the unit operators already think in, adjusted so that cranes of different sizes are compared on equal terms.

5. Why path length and not full cycle time calculation

A full physics-based cycle time (QC-NCT) requires 14+ crane-specific inputs including rated speeds, acceleration profiles, motion overlap capability, anti-sway settling times, and spreader lock/unlock durations. While precise, this approach creates standardization challenges:

• OEMs use different motion profile assumptions

• Anti-sway performance depends on a combination of software, mechanical design, and rope geometry — making it difficult to standardize across OEMs

• Simultaneous motion capabilities differ and are hard to verify

• A third party cannot easily reproduce the calculation

Reference Path Length captures the dominant variable, geometry, with a small number of measurements that can be verified from any crane specification or drawing, making it straightforward to implement across terminals. It provides approximately 80% of the normalization accuracy of a full cycle time calculation.

6. Relationship to other KPIs

EMPH sits within a layered throughput framework:

• Rated MPH (from QC-NCT): equipment capability ceiling, calculated, not measured. A design parameter, not a KPI.

• NMPH (Net Moves Per Hour): operational productivity during working crane hours. Defined separately under its own TIC 4.0 KPI definition.

• EMPH (this KPI): NMPH normalized for crane size. Enables cross-terminal comparison regardless of crane dimensions.

• GMPH (Gross Moves Per Hour): delivered throughput including all system effects. Primary commercial/service KPI.

• BMPH (Berth Moves Per Hour): system-level deployment incorporating crane allocation, splits, and berth strategy.
  
  

7. Intended use

EMPH supports:

• Cross-terminal crane benchmarking regardless of crane size or OEM

• Fleet performance assessment across mixed crane populations

• Identifying underperforming cranes relative to their size class

• Procurement evaluation: comparing crane ROI across different sizes
  
  

8. Scope limit: Performance vs Capacity

EMPH is a performance KPI. It describes observed, size-normalized productivity. It is not a capacity estimate. Capacity modeling requires additional assumptions (staffing, availability, utilization, TEU mix, peak factors) that are outside the scope of this metric.

9. Known limitations

• RPL uses linear (square) motion paths, not arced paths from simultaneous trolley and hoist motion. Arced motion reduces actual cycle time but introduces crane-specific speed and control
  variables that would compromise standardization.

• EMPH does not account for differences in rated trolley and hoist speeds between cranes of similar size. Speed is captured in the NMPH input.

• EMPH uses rated crane dimensions regardless of the vessel being worked. It is a fleet-level benchmarking metric, not a per-vessel-call metric.

• Cranes with non-standard configurations (e.g. waterside lashing platforms) may require adjusted measurements. These are considered edge cases.

• A future refinement could incorporate a speed weighting factor. The current geometry-only approach prioritizes adoptability and verifiability.

10. TIC4.0 data points:

• NMPH

  • tos|@|jobinstruction|@|order|move|counter|output|actual|box

• Dimensions

  • Outreach (O): che|sts01@|size|outreach|value

  • Rail span (S): che|sts01@|size|railspan|value

  • Backreach (B): che|sts01@|size|backreach|value

  • Max hoist height (H): che|sts01@|size|maxhoistheight|value

  • Portal: che|sts01@|size|portal|value

TIC Description

Required Information

M

1. Observed NMPH for the crane (from TOS or operational records)

2. Crane outreach (m) — from crane specification or drawing

3. Crane maximum hoist height above rail (m) — from crane specification

4. Crane backreach in meters (if using RPL-B) — from waterside rail CL to landside set position

5. Operational configuration: portal drop (RPL-P) or backreach drop (RPL-B)

TIC Description

SUBJECT

terminal, STS, TT, CHE, berth

CONCEPT

Value

Comparative moves per hour during crane execution

Related standards

O

TIC Description

Related TIC 4.0 definition

O

https://tic40.atlassian.net/l/cp/ZpGsxYZa

TIC Description

Example

M

Portal drop example (RPL-P):

Crane A: O = 65 m, S = 30 m, H = 50 m, NMPH = 28 RPL-P = 2 × (0.8 × 65 + 0.5 × 30) + 4 × (0.8 × 50) = 2 × 67.0 + 160.0 = 134.0 + 160.0 = 294.0 m EMPH = 28 × (294.0 / 265.2) = 31.0 EMPH

Crane B: O = 48 m, S = 25 m, H = 38 m, NMPH = 28 RPL-P = 2 × (0.8 × 48 + 0.5 × 25) + 4 × (0.8 × 38) = 2 × 50.9 + 121.6 = 101.8 + 121.6 = 223.4 m EMPH = 28 × (223.4 / 265.2) = 23.6 EMPH

Both report 28 NMPH. Crane A moves its spreader through 32% more space per cycle. EMPH makes this visible.

Backreach drop example (RPL-B):

Crane C: O = 65 m, S = 30 m, H = 50 m, B = 18 m, NMPH = 24 RPL-B = 2 × (0.8 × 65 + 30 + 18) + 4 × (0.8 × 50) = 2 × 100.0 + 160.0 = 200.0 + 160.0 = 360.0 m EMPH = 24 × (360.0 / 325.2) = 26.6 EMPH

Crane D: O = 48 m, S = 25 m, H = 38 m, B = 12 m, NMPH = 24 RPL-B = 2 × (0.8 × 48 + 25 + 12) + 4 × (0.8 × 38) = 2 × 75.4 + 121.6 = 150.8 + 121.6 = 272.4 m EMPH = 24 × (272.4 / 325.2) = 20.1 EMPH

Both report 24 NMPH on backreach. Crane C is doing significantly more work per cycle due to its longer trolley path. EMPH reveals the difference.

Reference crane: O = 55 m, S = 30 m, H = 46 m, B = 15 m

Reference RPL-P = 265.2 m
Reference RPL-B = 325.2 m

TIC Description

Example in the context of the grammar

M

Portal drop example (RPL-P):

Crane A: O = 65 m, S = 30 m, H = 50 m, NMPH = 28 RPL-P = 2 × (0.8 × 65 + 0.5 × 30) + 4 × (0.8 × 50) = 2 × 67.0 + 160.0 = 134.0 + 160.0 = 294.0 m EMPH = 28 × (294.0 / 265.2) = 31.0 EMPH

Crane A:

che|stsA@|size|outreach|value= 65
che|stsA@|size|railspan|value= 30
che|stsA@|size|maxhoistheight= 50
tos|@|jobinstruction|@|order|move|counter|output|actual|box = 28

RPL-P = 2 x (0.8 x che|stsA@|size|outreach|value= 65 + 0.5 x che|stsA@|size|railspan|value= 30) + 4 x (0.8 x che|stsA@|size|maxhoistheight= 50) = 2 x 67 + 160 = 134 + 160 = 294m

EMPH = 28 x (294.0/265.2) = 31.0

Crane B:

che|stsA@|size|outreach|value= 48
che|stsA@|size|railspan|value= 25
che|stsA@|size|maxhoistheight= 38

RPL-P = 2 x (0.8 x che|stsA@|size|outreach|value= 48 + 0.5 x che|stsA@|size|railspan|value= 25) + 4 x (0.8 x che|stsA@|size|maxhoistheight= 38) = 2 x 50 + 121.6 = 101.8 + 121.6 = 223.4m

EMPH = 28 x (223.4/265.2) = 23.6 EMPH

Both report 28 NMPH. Crane A moves its spreader through 32% more space per cycle. EMPH makes this visible.

TIC Description

Search tags

M

quay throughput, crane productivity, vessel ops

Technical

Version / Date

M

20260428

Technical

Internal TIC Version

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2026.019

Technical

Created by

Edited by

Review / Approve

Published

@Nic Westgate