Part IV — Ocean Freight
Vessel Types & Ocean Operations
The ships that carry the world's cargo — basic ship anatomy and the main vessel types, from container ships and ro-ros to bulk carriers, reefers and gas tankers.
A forwarder does not sail ships, but must understand them — because the vessel type determines what cargo can be carried, how it is loaded, which ports it can call at, and therefore the routing and cost. NAFL introduces the ship itself before the types, and so do we.
Basic ship anatomy
The working vocabulary every forwarder should recognise:
- Bow / bows — the front; stern — the rear. Forward (forrard) = toward the front; aft = toward the rear.
- Bridge — the command position from which the vessel is directed.
- Hold — the cargo space below deck; divided by hatches (the deck openings) and sometimes ‘tween decks (intermediate deck levels).
- Derricks — the ship’s own lightweight cranes for lifting cargo in and out of holds.
- Draught — how deep the vessel sits in the water (it determines which ports/canals it can use); freeboard — the hull height above the waterline.
- Double bottom — the space between inner and outer hull, used for fuel or water ballast.
Container ships
The workhorse of general cargo. Containers are stacked in slots both below deck and on top, each slot known to the ship’s mate, who is responsible for the cargo. Containers that must come off first — and dangerous goods, which may need rapid off-loading if they threaten the vessel — are stowed on deck.
A key operational fact: a large container ship cannot load or unload itself — it depends on the gantry cranes of a container terminal. This is why the biggest vessels only call at major equipped ports, and smaller feeder vessels distribute boxes to lesser ports.
Ro-Ro (roll-on / roll-off)
Vessels with bow, stern or side ramps onto which anything on wheels can be driven — cars, trucks, trailers, buses, heavy plant — alongside containers. The advantage is horizontal handling: no lifting gear needed, so heavy wheeled units load fast and the vessel turns around quickly. Ports like Sharjah handle ro-ros routinely.
Combi / multi-purpose vessels
Ships that carry a combination — containers, ro-ro cargo, break-bulk, reefer — usually smaller, with their own loading gear so they can serve ports lacking gantry cranes. In the Gulf they are widely used as feeder vessels, distributing cargo to smaller ports after it is offloaded from large container ships.
Reefer (refrigerated) vessels
Purpose-built for refrigerated cargo — either carrying reefer containers powered throughout the voyage, or with holds built as freezer compartments. They are complex (every hold/container needs continuous power and temperature monitoring) and often carry their own cranes, so they can load/unload without depending on port gantries.
Bulk carriers and specialised tankers
For large homogeneous cargoes that need no packing — loaded loose, by the shipload:
- Bulk carriers — ore, coal, grain, fertiliser, sugar, salt, cement.
- Tankers / VLCC — crude oil and liquids (also cooking oil, chemicals, petrol).
- OBO (“oil, bulk, ore”) — a multi-purpose bulk ship able to carry oil one way and dry bulk (grain, fertiliser, ores) the other, after high-pressure hold cleaning — reducing the costly empty “ballast” legs that plagued single-purpose bulk ships.
- LNG / LPG carriers — liquefied natural gas / petroleum gas, in multiple high-pressure refrigerated tanks; among the most hazardous and specialised vessels afloat.
Large, homogeneous quantities typically justify chartering a whole vessel rather than booking liner space (Chapter 14).
The vessel types are unchanged, but the scale has transformed. NAFL’s “large container vessel” of 2,000–6,000 TEU has been dwarfed by ultra-large container vessels of 24,000+ TEU. Two post-2003 forces every operator must now know: IMO 2020, capping marine-fuel sulphur at 0.5% and changing how ships are fuelled and surcharged; and the drive to decarbonise (LNG-fuelled, methanol and ammonia-ready ships now entering service). The chokepoint risk from Chapter 1 — Suez/Red Sea rerouting — bears directly on which vessels sail which routes. These are covered in Chapter 26.
Vessel knowledge turns into routing judgement. Whether cargo goes on a mainline container ship (major ports only) or needs a feeder to reach a smaller port; whether a project piece needs a ro-ro or combi with its own gear; whether perishables need a reefer service — these choices, made at quoting, decide transit time and cost. WorldZone’s hub-and-feeder reality (mainline to Jebel Ali/major GCC ports, feeders onward) is exactly the structure NAFL describes — knowing it lets an operator quote a realistic routing, not a wishful one.
What to take from this chapter
- Learn the anatomy vocabulary — bow/stern/hold/hatch/draught/derrick — it recurs in documents and bookings.
- Match cargo to vessel: container ship (needs gantry ports), ro-ro (wheeled), combi/feeder (self-geared, small ports), reefer (temperature), bulk/tanker/OBO/gas (loose homogeneous cargo).
- Big container ships can’t self-load — hence the mainline + feeder structure that shapes routing.
- Scale and fuel rules (IMO 2020, decarbonisation) are the big post-2003 shifts — see Chapter 26.