A trailer for towing by a power vehicle is provided and generally includes a frame and a tandem wheel assembly. The frame forms an undercarriage chassis which the tandem wheel assembly is positioned there under. The undercarriage chassis includes a steerable rear wheel assembly, a steerable front wheel assembly, and an extension assembly moving the front wheel assembly between trailing position and a self-propelled position where the rear wheel assembly and the front wheel assembly are positioned to equally support the undercarriage chassis.

A trailer for towing by a power vehicle is provided and generally includes a frame and a tandem wheel assembly. The frame forms an undercarriage chassis which the tandem wheel assembly is positioned there under. The undercarriage chassis includes a rear wheel assembly, a front wheel assembly, and an extension assembly moving the front wheel assembly between trailing position and a self-propelled position. At least one of the wheel assemblies is powered by a selectively engageable drive assembly including a motor, transmission, driveshaft, selectively engageable clutch and hub, to drive the rotation of at least one of the wheels.

A trailer for towing by a power vehicle is provided and generally includes a frame and a tandem wheel assembly. The frame forms an undercarriage chassis which the tandem wheel assembly is positioned there under. The undercarriage chassis includes a steerable rear wheel assembly, a steerable front wheel assembly, and an extension assembly moving the front wheel assembly between trailing position and a self-propelled position where the rear wheel assembly and the front wheel assembly are positioned to equally support the undercarriage chassis.

A two-axis spherical wheel or ball-wheel is provided wherein hemispheres (or spherical caps) rotate independently about a transverse or spherical axis and rotate dependently about an axial or longitudinal axis. In this way, a ball-wheel supports a vehicle chassis and drives (e.g., translates or rotates) the vehicle in any direction. Systems of ball-wheels are also disclosed. Two, three, four, or more ball-wheels can be joined in a system to support, translate, and/or rotate a vehicle without requiring the vehicle to turn. The ball-wheels include protective features to prevent debris from entering a drive system. Protective features may include springs and/or dampers to absorb impact forces on the vehicle chassis. Orienting the ball-wheels about a center point of the vehicle chassis enhances support and control of the vehicle.

All-terrain construction vehicles are provided that can include: a central frame; a pair of axles, each of the axles extending substantially normally across an axis of the central frame and pivoting in relation thereto; and at least two pairs of wheels. The vehicles can include at least two pairs of levelers. The vehicles can include out-rigging operatively extending above the one axis and between an operator cab and fluid pump unit in at least one configuration, the pump and fluid therefrom operatively coupled to the axles and wheels, the axles, wheels, and pump being operatively controlled via an operator interface within the operator cab. The vehicle can include levelers along the one side of the axis of the frame configured to support a utility pole above the hydraulic fluid pump unit.

All-terrain construction vehicles are provided that can include: a central frame; a pair of axles, each of the axles extending substantially normally across an axis of the central frame and pivoting in relation thereto; and at least two pairs of wheels. The vehicles can include at least two pairs of levelers. The vehicles can include out-rigging operatively extending above the one axis and between an operator cab and fluid pump unit in at least one configuration, the pump and fluid therefrom operatively coupled to the axles and wheels, the axles, wheels, and pump being operatively controlled via an operator interface within the operator cab. The vehicle can include levelers along the one side of the axis of the frame configured to support a utility pole above the hydraulic fluid pump unit.

All-terrain construction vehicles are provided that can include: a central frame; a pair of axles, each of the axles extending substantially normally across an axis of the central frame and pivoting in relation thereto; and at least two pairs of wheels. The vehicles can include at least two pairs of levelers. The vehicles can include out-rigging operatively extending above the one axis and between an operator cab and fluid pump unit in at least one configuration, the pump and fluid therefrom operatively coupled to the axles and wheels, the axles, wheels, and pump being operatively controlled via an operator interface within the operator cab. The vehicle can include levelers along the one side of the axis of the frame configured to support a utility pole above the hydraulic fluid pump unit.