# SiteCheck Trade & Energy – Vessel Deadweight Tonnage Calculator

> SiteCheck Trade & Energy – Vessel Deadweight Tonnage Calculator is a paid API for AI agents from api.tradeenergy-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Estimates vessel displacement and deadweight tonnage from hull dimensions (length, beam, draught, block coefficient) using standard naval architecture formulas, with optional cargo capacity calculation.

## Facts

- Endpoint: GET https://api.tradeenergy-api.workers.dev/api/logistics/deadweight-tonnage-calc?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sitecheck-trade-energy-vessel-deadweight-tonnage-calculator-167c47fc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_o3BN7Zka2YNxuHPdjKytH

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability sitecheck-trade-energy-vessel-deadweight-tonnage-calculator-167c47fc
```

Example prompt: Can you estimate the displacement and deadweight tonnage for a bulk carrier that's 180 metres long, 30 metres beam, 10 metres draught, with a block coefficient of 0.80 in seawater — lightship weight is 9000 tonnes and we have 500 tonnes of consumables on board?

## When to prefer this

Use this endpoint when you need a quick, formula-based estimate of vessel displacement or deadweight at the design stage, feasibility study, or cargo planning phase — without access to official stability booklets or ship registries. Ideal for naval architecture calculations, freight capacity modelling, or logistics planning where only hull dimensions are known. Not suitable when official certified DWT from classification records is required.

## Known failure modes

- Missing required parameters (lengthM, beamM, draughtM) returns an error
- Block coefficient outside 0.35–0.90 range may yield unrealistic results
- Lightship weight greater than displacement produces negative or null deadweight
- Invalid numeric strings for dimension parameters cause parse errors
- Omitting lightship weight means deadweight and cargo capacity return null

## How this service works

Vessel displacement and deadweight estimate from hull dimensions: volume = length × beam × draught × block coefficient; displacement = volume × water density (sea 1.025, fresh 1.000 t/m³); deadweight = displacement − lightship weight (if given). Also returns the cargo capacity left after fuel, stores and ballast you enter. A design-stage estimate from standard formulas, not a vessel's official DWT; no ship registry lookup.

## Output

Returns a JSON object with the computed underwater hull volume (m³), displacement in tonnes, deadweight tonnage (if lightship weight is provided), remaining cargo capacity (if consumables are provided), the water density used, and a note clarifying this is a design-stage estimate rather than an official DWT from class records.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "lengthM",
      "beamM",
      "draughtM"
     ],
     "properties": {
      "beamM": {
       "type": "string",
       "description": "Moulded breadth in metres (required)"
      },
      "water": {
       "type": "string",
       "description": "sea (default, 1.025 t/m³) or fresh (1.000 t/m³)"
      },
      "lengthM": {
       "type": "string",
       "description": "Length between perpendiculars in metres (required)"
      },
      "draughtM": {
       "type": "string",
       "description": "Draught in metres (required)"
      },
      "lightshipTonnes": {
       "type": "string",
       "description": "Optional lightship weight in tonnes, to get deadweight"
      },
      "blockCoefficient": {
       "type": "string",
       "description": "Block coefficient Cb, 0.35-0.90 (default 0.75; tankers/bulkers ~0.8-0.85, container ships ~0.6-0.7)"
      },
      "consumablesTonnes": {
       "type": "string",
       "description": "Optional fuel, fresh water, stores and ballast on board, tonnes"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "note": "Estimate from hull dimensions; the official DWT is in the vessel's stability booklet / class records.",
  "inputs": {
   "beamM": 30,
   "lengthM": 180,
   "draughtM": 10,
   "blockCoefficient": 0.8,
   "waterDensityTPerM3": 1.025
  },
  "deadweightTonnes": 35280,
  "displacementTonnes": 44280,
  "underwaterVolumeM3": 43200,
  "cargoCapacityTonnes": null
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sitecheck-trade-energy-vessel-deadweight-tonnage-calculator-167c47fc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.tradeenergy-api.workers.dev](https://www.zero.xyz/host/api.tradeenergy-api.workers.dev/llms.txt)