When a working shipyard needs to demolish and rebuild a primary wharf while keeping the port fully operational, few crane fleets are up to the task. The Halifax Shipyard Modernization Program in Nova Scotia faced exactly this challenge: replace an aging wharf with a new 850-foot-long, 65-foot-high structure without halting shipyard activity. The solution involved four Manitowoc crawler cranes operated by Irving Equipment Limited, deployed in a coordinated sequence of drilling, boring, falsework placement, and heavy lifting. This project shows how Crawler Cranes in Highway Construction How the Manitowoc machines deliver precision under constrained site conditions.
Project Overview: The Halifax Shipyard Wharf Replacement
The Halifax Shipyard, on the eastern coast of Canada, required complete demolition and reconstruction of an existing wharf as part of its national shipbuilding modernization effort. The new wharf measures approximately 850 feet in length and 65 feet in height, providing upgraded capacity for modern vessel servicing, including naval and commercial ships that require deeper drafts and heavier shore-side support. The project team had to design a structure that could withstand the harsh marine environment of the North Atlantic while accommodating the daily operational demands of an active ship repair facility.
Timeline and Key Constraints
The project ran from May 2013 through January 2014, spanning nine months of continuous work. Several critical constraints drove the planning:
- The wharf site remained within an active, operational port throughout demolition and construction
- Marine sediment overburden required specialized drilling equipment capable of handling mixed soil conditions
- Steel debris from the original wharf structure had to be bored through before new pile foundations could be installed
- Temporary falsework frames needed precise positioning to support concrete formwork within tight tolerances
- The work schedule had to accommodate shipyard vessel movements, tugboat traffic, and ongoing dock operations
Manitowoc crawler cranes were selected for their combination of lifting capacity, on-site mobility, and the ability to work on variable waterfront ground conditions where wheeled cranes would have struggled with load distribution.
The Crane Fleet: Four Manitowoc Machines Deployed
Irving Equipment Limited, based in Saint John, New Brunswick, supplied and operated the crane fleet. The four models were matched to lift weights, reach requirements, and spatial constraints, with each crane having a defined role so work could continue on multiple fronts.
Manitowoc 2250: Primary Drill and Heavy Lift Crane
The 300-ton Manitowoc 2250 crawler crane served as the primary workhorse of the project. With a 160-foot boom, it operated a Berminghammer drill for the most technically demanding foundation tasks. The 2250 is a lattice-boom crawler crane known for handling heavy attachments at extended radii, making it well suited for marine foundation work where the crane must reach over water while maintaining stability on prepared crane pads. Its ability to both drill and lift eliminated the need for a separate drill rig on site, reducing congestion.
Manitowoc 888: Medium-Capacity Support
The 230-ton Manitowoc 888 crawler crane with a 140-foot boom handled material placement, equipment positioning, and site logistics. This model offers a strong balance of capacity and footprint, allowing it to operate in tighter areas of the shipyard where the larger 2250 could not maneuver easily. The 888 served as the intermediate lift option, handling loads that were too heavy for the 12000s but did not justify tying up the 300-ton machine.
Two Manitowoc 12000 Crawler Cranes
The fleet included two 120-ton Manitowoc 12000 crawler cranes, rigged with 120-foot and 140-foot booms respectively. These operated as support units, handling material delivery, assisting with falsework assembly, and managing the wide range of auxiliary lifts that a wharf reconstruction generates. Having two identical cranes on site simplified parts inventory, maintenance planning, and operator training. When one crane was engaged in a long-duration lift, the other could handle unexpected tasks without delaying the overall schedule.
Crane Specifications Comparison
| Crane Model | Capacity (Tons) | Boom Length | Primary Role |
|---|---|---|---|
| Manitowoc 2250 | 300 | 160 ft | Drill operation, heavy lifts, falsework |
| Manitowoc 888 | 230 | 140 ft | Medium lifts, material handling |
| Manitowoc 12000 (Unit 1) | 120 | 120 ft | General support, assembly |
| Manitowoc 12000 (Unit 2) | 120 | 140 ft | General support, positioning |
This mix gave the project team flexibility to match crane capability to lift requirements, avoiding the inefficiency of using a high-capacity crane for smaller tasks that the support cranes could handle.
Construction Methods: Drilling, Boring, and Falsework
The technical core of the wharf reconstruction involved three distinct operations, each requiring different crane configurations and tooling. The Manitowoc 2250 with the Berminghammer drill performed the most demanding tasks, while the other cranes supported material flow and assembly work.
Overburden Drilling through Marine Sediment
The first stage required drilling through overburden consisting of marine sediment, small boulders, and rock sockets. Marine drilling presents challenges not encountered in land-based work:
- Water saturation reduces soil cohesion, making borehole stability difficult to maintain
- Variable sediment layers require the operator to adjust penetration rates continuously as the drill encounters different materials
- Scattered boulders within the sediment can deflect drill strings without appropriate tooling and impact energy
- Tidal fluctuations affect the working elevation of the crane and drill assembly, requiring frequent adjustment to maintain alignment
The Berminghammer drill provided the impact energy to fracture boulders while maintaining precision for foundation alignment, eliminating the need for a separate drill rig and reducing congestion in the constrained work area.
Boring through Steel Debris
The original wharf had been built decades earlier, and its demolition left substantial steel debris embedded in the seabed including old piles, reinforcement bars, mooring hardware, and abandoned utility supports. The Manitowoc 2250 with specialized hardened cutting tooling bored through this debris without requiring underwater cutting torches or divers, saving significant time and reducing safety risks associated with underwater demolition. This ability to handle both soil and steel in a single operation was a major factor in the project’s nine-month completion timeline.
Temporary Falsework Positioning
Once foundation elements were installed, temporary falsework frames were placed to support formwork for the wharf deck. Marine falsework must meet several requirements: it must be strong enough to support wet concrete loads, adjustable for variable seabed conditions and pile cutoff elevations, removable after curing without damaging the finished structure, and resistant to wave action during construction. The Manitowoc 2250 positioned these frames using its load moment indicator and boom-angle monitoring systems for real-time feedback during placement.
Operational Challenges in a Live Shipyard
Working within an active shipyard added complexity beyond crane operations. Every lift had to be coordinated with port traffic controllers, crane swing paths crossed active work zones, and noisy operations had to be scheduled around other shipyard activities.
Coordination with Port Operations
The Halifax Shipyard handles vessel repair, maintenance, and refit work for commercial and naval ships. During the wharf reconstruction, ships continued to dock at adjacent berths. Crane operators and site supervisors maintained constant communication with the port authority to ensure crane movements did not interfere with vessel traffic and that vessel schedules did not disrupt critical concrete pours or pile installations requiring continuous activity.
Safety Protocols for Over-Water Lifts
Operating cranes over water introduces specific safety considerations that land-based operators may not routinely encounter:
- Loss of load visibility: Loads descending below wharf deck level pass out of the operator’s direct line of sight, requiring a dedicated signalperson with radio communication
- Swing radius awareness: Crane superstructure rotation over water requires exclusion zones for small craft and diving operations
- Wind effects over open water: Marine winds are typically stronger and more gusty than inland conditions, affecting load stability at extended radii
- Tidal movement: Rising and falling water levels change the effective lift height and require sling length adjustments between tides
Irving Equipment Limited implemented all of these protocols as standard procedure, resulting in nine months of construction with no major incidents.
Equipment Selection Lessons
Using multiple crane types rather than a single large unit provided redundancy and parallel work capability. While the Manitowoc 2250 handled drilling, the two Manitowoc 12000s kept material handling progressing on other parts of the site. Crawler cranes proved superior to barge-mounted units because they could move independently between work zones without requiring tugboat assistance or barge repositioning. For a broader look at similar heavy lifting in constrained marine environments, see Cranes Working 24 7 At the Panama Canal.
Foundation Engineering and Pile Installation
A wharf of this scale requires a foundation system resisting lateral berthing loads, earth pressure from retained fill, and vertical deck loads. The Halifax wharf used driven piles installed to competent bearing strata below the marine sediment and debris.
Pile Types for Marine Wharves
| Pile Type | Application | Advantages | Installation Method |
|---|---|---|---|
| Steel H-piles | High vertical and lateral loads | High capacity, predictable driving | Impact or vibratory hammer |
| Concrete piles | Corrosive environments | Durable, fire resistant | Precast driven or cast-in-situ |
| Steel pipe piles | Deep foundations through debris | Can be drilled through obstructions | Driven, then cleaned out |
| Timber piles | Light loads, historic use | Low cost, renewable | Impact hammer driving |
For the Halifax project, the presence of steel debris made pile installation more complex than a greenfield site. The Berminghammer drill cleared obstructions before the pile driving rig moved into position. This drill-and-drive sequence is standard practice in urban waterfront projects where previous construction leaves behind buried obstacles that could damage pile driving equipment or cause refusal.
Load Testing and Quality Assurance
Each production pile underwent load testing. Static load tests applied incremental loads while measuring settlement, and dynamic testing using a pile driving analyzer provided real-time capacity estimates during installation, ensuring the foundation would perform reliably for decades.
Conclusion: Crawler Crane Versatility in Marine Infrastructure
The Halifax Shipyard wharf reconstruction demonstrates how carefully selected crawler crane fleets can deliver complex marine infrastructure projects without shutting down the facility they are upgrading. Four Manitowoc cranes a 300-ton 2250, a 230-ton 888, and two 120-ton 12000s each played a defined role in a choreographed sequence of demolition, drilling, falsework erection, and concrete placement. The equipment selection matched site conditions: crawler tracks provided waterfront mobility, the 2250 delivered the reach and capacity for heavy drill attachments, and the support cranes kept material flowing without bottlenecks. For engineers planning similar projects, the Halifax model shows that crane fleets can handle the full spectrum of marine construction tasks when deployed with proper planning and experienced operators.
Understanding the design principles behind lifting equipment is essential for structural engineers. For details on a common facility crane type, see Overhead Travelling Cranes and Their Design Considerations. For heritage structure crane work, Keeping an Old Chimney Working 3 illustrates lifting equipment integration with preservation projects.