LIVEdataset aec-bench@releasetasks 552models 18last submission … · built …
maritimewith-tool

Block Coefficient

Calculates the block coefficient C_B used throughout the IACS Harmonised Common Structural Rules for Bulk Carriers and Oil Tankers (CSR-H): C_B = Delta / (1.025 x L x B x T_SC), where Delta is the moulded displacement of the ship at draught T_SC (tonnes), L is the Rule length (m), B is the moulded breadth (m), and T_SC is the scantling draught (m). C_B is a fundamental principal-particulars quantity used throughout CSR-H scantling assessments.

with-tool: The model is given an executable Python calculator script.

Standards

IACS CSR-H (Common Structural Rules) 01 JUL 2025, Pt 1 Ch 1 Sec 4, §3.1.8

Tags

block-coefficientcsr-hdeterministiciacsmaritimeprincipal-particulars

How this task is generated

One template produces many comparable benchmark tasks while keeping the scoring contract fixed.

  1. 01

    Template

    The reusable contract shown on this page.

  2. 02

    Scenario

    An archetype and site context are sampled.

  3. 03

    Difficulty tier

    Inputs may be hidden at harder tiers.

  4. 04

    Task prompt

    The model responds with the declared outputs.

Parameters

Inputs the model receives, and the outputs it is scored on.

Inputs

4 inputs

Always given

Included directly in every task prompt.

3

  • Rule length L

    rule_length_L_m

    Rule length L

    130 – 340 m

  • Moulded breadth B

    moulded_breadth_B_m

    Moulded breadth B

    20 – 65 m

  • Scantling draught TSC

    scantling_draught_TSC_m

    Scantling draught T_SC

    8 – 24 m

Derived from scenario

Sampled from the scenario and inferable from its description.

1

  • Moulded displacement

    moulded_displacement_t

    Moulded displacement of the ship at the scantling draught T_SC (Delta)

    Derived from the archetype scenario. Hidden at hard difficulty.

    15000 – 400000 t

Scored outputs

1 output

Block coefficient CB

block_coefficient_CB

Block coefficient C_B (dimensionless)

Scores if within ±3% of the reference value.

Difficulty

Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.

easy

All inputs given

All parameters given for a large, conventional bulker or tanker

medium

All inputs given

All parameters given across the full range of ship types

hard

Some inputs hidden

Moulded displacement hidden; agent must infer it from the vessel description

Hidden inputs

  • Moulded displacement tmoulded_displacement_t

Prompt replacement text

The vessel is a {{ archetype.description }} ({{ archetype.site_context }})

Task bundle

The exact instruction and parameter contract used to generate this task, pinned to the published library source.

/workspace

  • instruction.md
  • block-coefficient_calc.py

Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.

1You are a senior naval architect specializing in classification society rule compliance.2 3## Problem4 5Calculate the IACS Block coefficient C_B for a ship under the Harmonised Common Structural Rules (CSR-H).6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11{% if moulded_displacement_t is defined %}12| Moulded displacement at T_SC (Delta) | {{ moulded_displacement_t }} | t |13{% endif %}14| Rule length (L) | {{ rule_length_L_m }} | m |15| Moulded breadth (B) | {{ moulded_breadth_B_m }} | m |16| Scantling draught (T_SC) | {{ scantling_draught_TSC_m }} | m |17{% if archetype_description is defined %}18 19### Vessel Context20 21{{ archetype_description }}22{% endif %}23 24{% if tool_available %}25## Available Tool26 27A Block coefficient calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:28 29```bash30python3 /workspace/{{ meta.name }}_calc.py --help31```32 33You may use this tool to verify your calculations or compute values directly.34{% endif %}35 36## Required37 38Calculate the following:39 401. Block coefficient C_B (dimensionless)41 42## Applicable Standards43 44- IACS Harmonised Common Structural Rules (CSR-H), edition 01 JUL 2025, Pt 1 Ch 1 Sec 4 §3.1.845 46## Constraints47 48- No internet access is available. Work from engineering knowledge and the provided tool.49- Quote from Pt 1 Ch 1 Sec 4 §3.1.8: "C_B, the block coefficient at the draught, T_SC is defined in the following equation: C_B = Delta / (1.025 x L x B x T_SC)" where Delta is the moulded displacement of the ship at draught T_SC (in tonnes), L is the Rule length (m), B is the moulded breadth (m), and T_SC is the scantling draught (m).50- Use a seawater density of 1.025 t/m^3, per the formula above.51{% if moulded_displacement_t is not defined %}52- The moulded displacement is not given directly — infer an appropriate value from the vessel description above.53{% endif %}54 55## Output Format56 57Show your step-by-step working in Markdown, including formulas and intermediate calculations. At the end of your solution, include a JSON block with your final answer in exactly this format:58 59```json60{61 "block_coefficient_CB": <numeric_value>62}63```64 65Write your complete solution to `/workspace/output.md`.66

Scenario archetypes

Each generated task is drawn from one of these realistic scenario bands.

Site contexts ground each scenario in a real locale the model can use to infer hidden values.

Capesize bulk carrier

capesize_bulk_carrier

Capesize bulk carrier with a moulded displacement of approximately 190,000 tonnes at the scantling draught

capesize-iron-ore-runcapesize-coal-run
Parameter ranges
moulded_displacement_t
186200 – 193800
rule_length_L_m
274 – 286
moulded_breadth_B_m
44 – 46
scantling_draught_TSC_m
17.6 – 18.4

Vlcc tanker

vlcc_tanker

VLCC (Very Large Crude Carrier) with a moulded displacement of approximately 366,000 tonnes at the scantling draught

arabian-gulf-crude-exportwest-africa-crude-export
Parameter ranges
moulded_displacement_t
358000 – 374000
rule_length_L_m
323 – 337
moulded_breadth_B_m
58.8 – 61.2
scantling_draught_TSC_m
21.5 – 22.5

Container ship

container_ship

Large container ship with a moulded displacement of approximately 125,000 tonnes at the scantling draught

asia-europe-trade-lanetranspacific-trade-lane
Parameter ranges
moulded_displacement_t
118000 – 132000
rule_length_L_m
295 – 325
moulded_breadth_B_m
43 – 47
scantling_draught_TSC_m
12.8 – 14.2

General cargo

general_cargo

General cargo ship with a moulded displacement of approximately 23,500 tonnes at the scantling draught

short-sea-general-cargocoastal-breakbulk-trade
Parameter ranges
moulded_displacement_t
22800 – 24200
rule_length_L_m
145 – 155
moulded_breadth_B_m
22.3 – 23.7
scantling_draught_TSC_m
8.7 – 9.3

Example task

capesize-iron-ore-run-capesize-bulk-carrier-preview — hard difficulty, some inputs hidden.

Capesize bulk carrier with a moulded displacement of approximately 190,000 tonnes at the scantling draught. capesize-iron-ore-run. Required outputs: block_coefficient_CB

The model sees

Scenario context and visible inputs.

rule_length_L_m
274 to 286 m
moulded_breadth_B_m
44 to 46 m
scantling_draught_TSC_m
17.6 to 18.4 m

Executable tool: block-coefficient_calc.py

The model must infer

Inputs withheld at this difficulty.

  • Moulded displacement t

    moulded_displacement_t

Stand-in text in the prompt

The vessel is a {{ archetype.description }} ({{ archetype.site_context }})

The model must produce

The scored JSON answer schema.

{
  "block_coefficient_CB": <number>
}
  • block_coefficient_CB · scored within ±3%