Navalyze · Bulk carrier · Ship

IRON DUKE

IMO: 9577422
Type: Bulk carrier
Average cargo carried: 34,558 t
Flag (estimated): United Kingdom
Port of registry: London
Technical efficiency: EEXI 4.10 g CO₂/t·nm
Former names: MARIA

ISM company (DoC holder) in 2025: RUBICON MARITIME (UK) LIMITED

Report year

2021 at a glance

From the 2021 THETIS-MRV report. Carries about 9,161 t of cargo on average.

Fuel kg/nm

94.2

Bulk carrier median 91.4 kg/nm (+3%)

CO₂ per transport work (cargo)

32.3

g CO₂/t·nm · Bulk carrier median 8.57 (+277%)

Average speed

12.3 kn

Bulk carrier median 11.5 kn (+7%)

Fuel per day at sea

27.7 t/day

Fuel consumed

743 t

CO₂ emitted

2,333 t

Distance sailed

7,891 nm

CO₂ ÷ CO₂ per mile

Time at sea

644 h

27 days, 7% of the year

Within the bulk carrier fleet, 2025

Set against all 3,611 bulk carrier ships with a full-year 2025 report. Bigger ships burn more per mile but less per tonne of cargo, so read fuel per mile with the ship's size in mind.

Fuel kg/nmThis ship 93.7 kg/nm · median 82.6 (+13%)

61.0Ranks 2,596 of 3,611, lowest first114

Average speedThis ship 8.4 kn · median 10.7 (−21%)

8.8Faster than 8% of bulk carrier ships11.8

CO₂ per transport work (cargo)This ship 8.48 g CO₂/t·nm · median 7.90 (+7%)

4.80Ranks 2,080 of 3,611, lowest first15.9

Middle 80% of shipsMiddle 50%Bulk carrier medianThis ship

Where the emissions happen, 2021

THETIS splits each ship's CO₂ by voyage type. The split sets how much falls under the EU ETS: all of it within the EU and at berth, half of it on voyages into or out of the EU.

Between EU ports0%
From the EU56%
Into the EU43%
At berth in the EU1%

Fuel burned laden

–

Not reported

CO₂ at berth

22 t

0.9% of the ship's CO₂, alongside in EU ports

Methane (CH₄)

–

Mainly from LNG; small for oil, biofuel and methanol

CO₂eq uplift

–

CO₂eq on top of CO₂ alone, from CH₄ and N₂O

Over the years

Full-year reports only. The Bulk carrier median is the middle ship of all bulk carrier ships reporting that year; it moves with the fleet, so a ship can gain on it without changing itself.

Fuel kg/nm

IRON DUKE
Bulk carrier median

80.0100.0120.0140.0

’182018’192019’202020’212021’222022’232023’242024’252025

Average speed, kn

IRON DUKE
Bulk carrier median

8.09.010.011.012.013.0

’182018’192019’202020’212021’222022’232023’242024’252025

CO₂ per transport work (cargo), g CO₂/t·nm

IRON DUKE
Bulk carrier median

0.010.020.030.040.0

’182018’192019’202020’212021’222022’232023’252025

Year on year

Year	Average speed	Fuel kg/nm	Fuel per day at sea	Distance	CO₂ per transport work	Reading
2024→2025	−2.3 kn	−4%	−25%	−72%	–	2.3 kn slower, fuel per mile down 4%; worse than speed alone explains (fouling, weather, loading or trade).
2023→2024	+0.9 kn	−30%	−22%	+466%	–	0.9 kn faster, fuel per mile down 30%; better than speed alone explains (hull, engine or trade).
2022→2023	−1.0 kn	+34%	+20%	−64%	+26%	1.0 kn slower, fuel per mile up 34%; worse than speed alone explains (fouling, weather, loading or trade).
2021→2022	−1.5 kn	+10%	−3%	+148%	−79%	1.5 kn slower, fuel per mile up 10%; worse than speed alone explains (fouling, weather, loading or trade).
2020→2021	+1.0 kn	−21%	−14%	−62%	+247%	1.0 kn faster, fuel per mile down 21%; better than speed alone explains (hull, engine or trade).
2019→2020	+1.7 kn	+7%	+26%	+10%	+2%	1.7 kn faster, fuel per mile up 7%; better than speed alone explains (hull, engine or trade).
2018→2019	−0.8 kn	−7%	−15%	+78%	−28%	0.8 kn slower, fuel per mile down 7%; worse than speed alone explains (fouling, weather, loading or trade).

Fuel per mile rises roughly with the square of speed for a given ship, so a change in speed explains much of a change in fuel per mile.

Every reporting year

One row per THETIS-MRV report. A ship that changed operator during a year has a part-year report for each.

Operation

Year	ISM company	Fuel t	CO₂ t	Distance nm	Hours at seah	Average speedknots at sea	Fuel kg/nmthis ship	CO₂ per transport work (cargo)g/t·nm, this ship	Laden fuel
2025	RUBICON MARITIME (UK) LIMITED	1,036	3,239	11,051	1,317	8.4	93.7	8.48	–
2024	RB BRITISH MARINE (UK) LIMITED	3,874	12,159	39,696	3,697	10.7	97.6	–	–
2023	not published	971	3,058	7,012	719	9.8	139	8.44	–
2022	not published	2,026	6,330	19,535	1,808	10.8	104	6.70	–
2021	not published	743	2,333	7,891	644	12.3	94.2	32.3	–
2020	not published	2,486	7,775	20,944	1,848	11.3	119	9.29	–
2019	not published	2,118	6,619	19,014	1,987	9.6	111	9.09	–
2018	not published	1,286	4,018	10,682	1,023	10.4	120	12.5	–

Benchmark and verification

Year	ISM company	CO₂ per TW, g CO₂/t·nm	Bulk carrier median	vs Bulk carrier	Rank	Verifier	Methods
2025	RUBICON MARITIME (UK) LIMITED	8.48	7.90	+7%	2,080 of 3,611	ClassNK	A
2024	RB BRITISH MARINE (UK) LIMITED	–	–	–	–	ClassNK	A
2023	not published	8.44	8.27	+2%	1,845 of 3,548	ClassNK	A
2022	not published	6.70	8.71	−23%	1,028 of 3,968	ClassNK	A
2021	not published	32.3	8.57	+277%	3,431 of 3,466	ClassNK	A
2020	not published	9.29	8.24	+13%	1,962 of 3,150	DNV	B
2019	not published	9.09	8.38	+8%	1,952 of 3,360	DNV	B
2018	not published	12.5	8.50	+48%	2,765 of 3,384	DNV	B

Fuel per mile and CO₂ per tonne-mile are the ship's own reported KPIs. Bulk carrier ships are benchmarked on CO₂ per transport work (cargo) (TW), in g CO₂/t·nm. CO₂eq adds methane and nitrous oxide and is in the public files from 2024. Rank counts from the lowest figure among that year's bulk carrier ships. Methods: A delivery notes, B tank monitoring, C flow meters, D direct measurement. FuelEU GHG intensity is not shown: it needs fuel types, which the public file does not carry. Operators are named only from 2024, the first year the public files carry them; earlier years belong to the ship, not to any company.