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Elevator types: hydraulic vs traction, travel limits, and shaft planning

One-line orientation

Elevator selection turns on building height, travel, and speed. Hydraulic systems generally suit low-rise buildings, while traction systems serve a wider range. Treat dimensions and speed ranges as planning guides, then confirm the selected product.

Key points

Hydraulic elevators (low-rise only — roughly 2–6 stories / about 50–60 ft of travel):

  • Use a piston/plunger beneath or beside the cab to push it up; gravity lowers it.
  • Slower, less energy-efficient, risk of oil leaks.
  • Three sub-types:
    • Inground (holed) hydraulic: steel plunger extends into a drilled hole below the shaft. This is the longest hydraulic-travel subtype: up to ~60 ft (~5–6 stories). Requires below-grade excavation.
    • Holeless hydraulic: the plunger avoids a deep jack bore below the pit. The elevator still needs a hoistway pit. Travel limit: up to ~40 ft (telescoping plunger; single-model figures vary). Preferred where below-grade digging is impractical.
    • Roped hydraulic: plunger moves inside an above-ground cylinder; ropes connected to the cab extend the reach. Travel limit: up to 60 feet (~5–6 stories).

Traction elevators (all building types):

  • Electric motor drives sheaves and cables; a counterweight offsets cab weight for efficiency.
  • Traction elevators are faster and more energy-efficient than hydraulic elevators. Maintenance varies by system.
  • Machine room traditionally at the top of the shaft (can be at bottom).
  • Three sub-types:
    • Geared traction: motor drives a gearbox → sheave. Geared traction: about 100–450 fpm. Best for low- to mid-rise. Noisier and less efficient at higher speeds.
    • Gearless traction: motor drives the sheave directly (no gearbox). Gearless traction: about 500–1,200 fpm. Standard for high-rise buildings.
    • Machine Room-Less (MRL): all machinery housed inside the shaft — no separate machine room. Commonly cited at 30–40% lower energy consumption — a manufacturer and planning figure, not a standard. It eliminates the traditional machine room, but still needs the required control and service space. Suitable for low- to mid-rise; increasingly common in commercial work.

Shaft planning examples:

  • Shaft depth: 7’–0” to 8’–2”
  • Shaft width: 8’–6” to 9’–6”
  • Must connect to emergency power in applicable building types
  • These are rough planning ranges, not fixed dimensions. Confirm the cab, door, hoistway, pit, overhead, control space, and emergency-power requirements for the selected product and code.

Common capacity and door examples:

  • 2,000–2,500 lb (small): single sliding door
  • 3,000–3,500 lb (mid): center-opening door
  • 4,000–5,000 lb (high): two-speed door

These pairings are examples, not automatic matches. Manufacturers offer several door and cab combinations for the same capacity.

Elevator families: the lifting system sets the travel ceiling

SCHEMATIC

Three shaft sections on one grade datum; above the 60 ft cap the territory is traction-only.

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Hydraulic, geared-traction, and gearless-traction elevators drawn as three shaft sections on one grade datum, with everything above the hydraulic travel cap marked as traction-only territory Three original, equal-width elevator shaft sections stand on one shared grade datum, indexed to a left-margin travel scale in feet ticked at 0, 20 and 40, with a blue tick and a blue cap line running the full width at 60 feet. Everything above that cap line is filled with a pale teal zone wash headed 'beyond hydraulic reach — traction only', so the cap reads as the edge of a territory rather than as a rule across the sheet. Every shaft shows conventional section anatomy: a car on guide rails, a pit with a spring buffer and a pit ladder. The hydraulic shaft is shortest — its head stops exactly at the lower edge of the teal zone and is labeled no overhead machine; a car sits over a blue below-car plunger whose ram telescopes into a buried cylinder casing in a jack hole below the pit, fed by a hydraulic power unit beside the shaft — the plunger physically limits travel to about two to six stories. The taller geared-traction shaft and the much taller gearless-traction shaft both stand well inside the teal zone, each carrying an overhead machine room on a slab holding a teal drive sheave and a motor block, with one continuous teal rope over the sheave hanging an identical car on one side and a narrow teal counterweight, on its own guide rails, on the other; clear overhead is marked above the car, and there is clear daylight between the geared and gearless tops. Blue carries the hydraulic plunger, cylinder, fluid line, and cap; teal carries the traction sheave, rope, counterweight, and the above-cap zone; neutral line carries shared structure; position, height, mechanism, and direct labels preserve every distinction without color. BEYOND HYDRAULIC REACH — TRACTION ONLY02040carcarcarhydraulic power unit60 ft — hydraulic capguide railsbelow-carplungercar buffercylinder casingin jack holeno overhead machinemotor +drive sheaveclear overheadcounterweightpit laddergeared machine (overhead)gearless machine (overhead)Hydrauliclow-rise · 2–6 storiesrise ≈50–60 ftGeared tractionlow- to mid-risespeed ≈100–450 fpmGearless tractionmid- to high-risespeed ≈500–1,200 fpm
  • hydraulic — below-car plunger; travel-capped
  • traction — overhead machine, ropes, counterweight
  • teal zone — above the cap, traction only

The plunger physically caps hydraulic travel at about 2–6 stories (50–60 ft): past that the FAMILY changes to traction — not the model.

Machine-room-less (MRL) traction puts the same machine inside the hoistway instead of a machine room; low- to mid-rise, up to about 500 fpm.

Confusions / comparison

TypeDrive mechanismTravel limitSpeedBest for
Inground hydraulicPlunger in drilled holeup to ~60 ft (~5–6 stories)LowLow-rise, where digging possible
Holeless hydraulicTelescoping plunger; no deep jack boreup to ~40 ftLowLow-rise where a deep bore is impractical
Roped hydraulicPlunger + ropes, above-groundup to ~60 ft (~5–6 stories)LowLow-rise, extended reach
Geared tractionMotor → gearbox → sheaveAll low/mid-riseAbout 100–450 fpmLow- to mid-rise
Gearless tractionMotor → sheave (direct)All high-riseAbout 500–1,200 fpmMid- to high-rise
MRL tractionMotor in shaftLow- to mid-riseUp to ~500 fpmSpace-efficient, energy-conscious

→ Vertical Transportation: escalators (specs, arrangements) · Code: accessibility (ADA elevator requirements, cab dimensions) · Structural: machine-room loads, pit waterproofing.

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