How to Identify Historic Double-Decker Bus Types by Their Stairs and Windows

Two details give away a vintage double-decker faster than a badge, a livery or a maker's plate: where the stairs sit, and how the windows are shaped. Learn to read those two features and you can stand at a rally, a museum yard or a roadside and make a sensible guess at when a bus was built, where its engine lives and how passengers got aboard.

You do not need chassis numbers or build lists to begin. What follows is a beginner's method, built entirely on things you can see from the pavement, with a notebook in one hand and a cup of tea in the other.

Start at the Back, Not the Front

Most of us walk to the front of a bus first, because that is where the interesting shapes are. Try the opposite. Go to the rear and ask one question: is there an open platform, or a door?

An open rear platform — a pole, a step up, a conductor's bell if you are lucky — tells you the bus belongs to the classic British rear-entrance tradition. The staircase will be just inside it, curving or rising straight up over the rear axle. You can often see the bottom steps through the open platform itself, which is the quickest confirmation you will ever get.

A front door, especially one sitting right beside the driver, points to the later front-entrance generation. On these buses the stairs climb immediately behind that door, usually over the front wheel. Stand outside and look at the front bay of side glazing: it is often narrower or differently shaped than the rest, because the staircase is running up behind it.

Three Stair Positions, Three Families

Once you start noticing stair position, buses begin sorting themselves into groups.

• Rear staircase, inside the platform. Half-cab front-engined buses and the rear-platform classics: AEC Regents, Leyland Titans, Bristol Ks and Lodekkas in some forms, and the Routemaster. Engine at the front; boarding at the back.
• Front staircase, just behind the front entrance. The rear-engined generation that took over from the late 1950s onwards: Leyland Atlanteans, Daimler Fleetlines, Bristol VRS and VRLs, Leyland Olympians. Engine at the back; boarding at the front.
• Centre or oddly placed staircase. Uncommon, and usually a sign of a municipal oddity, an export body or a rebuild. Treat it as a prompt to look harder rather than a category of its own.

What the Stairs Tell You About the Engine

The link between stairs and engine is strong, and it is worth memorising as a rule of thumb. If the stairs are at the front, the engine is almost certainly at the back — the drivetrain had to move somewhere once the entrance took the front corner. If the stairs are at the rear, the engine is at the front, either under a protruding bonnet with the driver in a separate half-cab, or under the floor with a full-width cab.

The Routemaster is the famous exception that proves the rule: front-engined, yet with a full-width cab and no bonnet ahead of the driver, and a rear platform entrance with the stairs at the back. When you meet a bus that seems to break the pattern, check whether the body has been rebuilt or the chassis re-bodied before you trust your first guess.

Windows: The Other Half of the Story

Count the bays, then compare the decks

Walk the length of one side and count the upstairs windows, then count the downstairs ones. On a traditional rear-entrance bus the two rows usually line up reasonably well. On front-entrance machines the lower deck often has fewer, deeper windows because the door and staircase have eaten into the front end.

Look closely at the bay directly above the stairs. It is frequently narrower, or set at a slightly different height, because the staircase needs headroom underneath it. That single odd window is a quiet giveaway of where the stairs climb.

Shallow upstairs windows mean a lowbridge body

Some operators needed double-deckers that would fit under low bridges and into tight depots. Two solutions appeared. One was to sink the upper-deck gangway between the seats, so passengers walked in a shallow trench; bodies built this way are usually called lowbridge. The other was simply to reduce overall height by shrinking the glazing.

From outside, both show up the same way: the row of upper-deck windows is noticeably shallower than the row below, and the horizontal band between the two decks looks unusually deep. If the upstairs windows look like letterboxes compared with the downstairs ones, you are probably looking at a low-height design rather than a standard one.

Ventilators, corners and front ends

Older bodies often give each window a separate small sliding pane at the top, with a visible horizontal frame line. Later buses tend to use larger single panes with a full-depth slider, and the frames get thinner and squarer as the years pass. Rounded, deeply curved corners and small panes suggest an earlier body; flatter panels, wrap-around front corner glass and one-piece screens suggest the 1960s.

The front end settles it. If you can see a bonnet poking out ahead of the lower windscreen, and the driver sits in a cab of their own on one side, you have a front-engined half-cab bus. If the front is a full-width flat face with the driver sitting behind glass at the very front, keep looking further back for the engine.

A Ten-Second Walk-Around Checklist

1. Check the rear: open platform or door?
2. Find the stairs: rear, front or somewhere odd?
3. Look for a bonnet ahead of the driver.
4. Count upper and lower window bays on one side.
5. Compare the height of the two rows of glazing.
6. Note the corner shape of the windows and any separate top ventilators.
7. Walk around and repeat on the other side — entrances and staircases are not always where you assume.

Practise Where the Buses Are Still

Rallies, transport museums and depot open days are ideal, because you can stand still and compare two vehicles side by side. Take photographs of the rear platform, the staircase and one full side view of each bus you like. After a dozen photographs you will start recognising layouts before you read the label, which is the whole point.

Look Twice Before You Decide

Livery tells you almost nothing reliable, and a bus that has been re-bodied, rebuilt or converted to open top can carry a confusing mixture of features. Use the stairs and the windows as your first filter, then let the details confirm or overturn your guess. Being wrong occasionally is part of the pleasure; the eye sharpens with every bus you walk around slowly.

Photo: Jimmy Liao / Pexels