Construction methods · Heavy lift, moving and accelerated construction

SPMT move (self-propelled modular transporters)

Multi-axle hydraulic transporters, computer-controlled and combined into one platform, drive under a complete superstructure built nearby, lift it, carry it to the crossing and lower it onto the piers. A 2,000 t bridge moves in a night; the transporters need only a level path.

How bridges get built · Heavy lift, moving and accelerated construction · SPMT move (self-propelled modular transporters)

Also called: SPMT, bridge move, transporter erection, roll-in

SPMT: 6-axle modules, computer-steeredset on the bearings overnightSPMT bridge move
Concept diagram (TheBridgeEng)

How it is done

  1. Build the superstructure on temporary supports at a staging area with SPMT access underneath.
  2. Drive the SPMTs under, lift with the axle hydraulics, transport at walking pace with jacking to keep the deck level over grade changes.
  3. Position over the bearings, lower, connect; remove the transporters before the road or rail reopens.

Where it fits

  • Replacement bridges over motorways and railways with a staging area within a few hundred metres; spans 20-100 m; steel or concrete decks up to 3,000-4,000 t.

Where it does not

  • Routes with grades over 6-8 % or soft ground without mats, decks too flexible for transport without strongbacks, sites without a staging area.

Plant, pace and money

PlantSPMT modules (4-6 axle lines each, 30-40 t per axle line), power packs, jacking towers, mats.
ProductivityOvernight moves; assembly months.
CostUSD 200,000-800,000 for the move; the temporary staging is the larger cost.

Risks and controls

What goes wrong

  • Hydraulic failure, ground failure under the transporters, deck stress during transport, clearance conflicts on the route.

Quality assurance

Route survey and ground bearing checks, transport analysis of the deck, trial lift, contingency procedures.

Examples

Dozens of US and Canadian ABC replacements, Dutch railway crossings, Korean expressway overpasses.

In the bridge game

What Bridge Master applies when you pick it

Deck types: Steel plate girder, Steel box girder, PSC I-girder, Steel truss, Orthotropic steel box, Steel arch, PSC U-girder, Spliced PSC girder, Precast segmental box, Voided slab, Network tied arch. Spans 30-90 m, up to 140 m.

  • +25: Overpass with a yard nearby: SPMT.
  • -45: SPMTs need ground.
  • +10: Feasible in a long possession if a haul path crosses the track at grade.
  • not allowed: SPMT over water.

Try it in the game →

Related methods

Lateral slide (slide-in bridge construction)Float-in of complete arches and spansPrecast segmental piers and caps

Further reading

FHWA Manual on Use of SPMTs to Remove and Replace Bridges · Mammoet and ALE engineering guides

← Lateral slide (slide-in bridge construction)Rotation (swing) construction →