AMENDED CLAIMS

received by the International Bureau on 30 September 2019 (30.09.2019)

I claim:

1. A system for blast-cleaning a barge bottom, supported on blocks in a work building, by a human operator, the system for blast-cleaning a barge bottom comprising:

(i) a blasting tractor adapted to move longitudinally along the underside of the barge and adapted to house an operator within eyesight of the blast- cleaning operation;

(ii) a transverse track beam mounted upon a front of said blasting tractor and extending outwardly from the tractor in a direction transverse to longitudinal movement of the tractor, said transverse track beam having longitudinal dimensions substantially similar to transverse dimensions of the barge bottom;

(iii) at least one positioning unit adapted to move along said transverse track beam; and

(iv) at least one blaster head mounted upon said positioning unit adapted to move with said positioning unit and move relative to said positioning unit; where, in use, said positioning unit with said blaster head is moved along said transverse track beam, and said blaster head is moved in relation to said positioning unit, under the control of the operator, such that all unblocked surfaces of the barge bottom are reached with blast media.

2. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head camera.

3. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head sensor.

4. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head sensor adapted to sense objects through a cloud of blast media.

5. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head sensor adapted to make sensor readings during pauses between pulses of blasting.

6. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head sensor adapted to determine absolute location from fixed reference beacons placed inside the work building. 15

7. The system for blast-cleaning a barge bottom of claim 1, where said blasting tractor further comprises an air filtration system.

8. The system for blast-cleaning a barge bottom of claim 1, where said blasting tractor further comprises an air supply system.

9. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head camera and a blaster-head sensor, where video from said blaster-head camera is recorded and is combined with recorded data from said blaster-head sensor to provide for a detailed inspection of all surfaces and fittings of the barge bottom before, during, and after blasting.

10. The system for blast-cleaning a barge bottom of claim 1, further comprising a blaster-head camera, where video from said blaster-head camera is recorded for later use in analyzing and investigating blasting operations.

1 l · A system for blast-cleaning a barge bottom, supported on blocks in a work building, robotically, the system for blast-cleaning a barge bottom comprising:

(i) a robotic blasting tractor adapted to move longitudinally along the underside of the barge;

(ii) a transverse track beam mounted upon a front of said robotic blasting tractor and extending outwardly from the tractor in a direction transverse to longitudinal movement of the tractor, said transverse track beam having longitudinal dimensions substantially similar to transverse dimensions of the barge bottom;

(iii) at least one positioning unit adapted to move along said transverse track beam;

(iv) at least one blaster head mounted upon said positioning unit adapted to move with said positioning unit and move relative to said positioning unit;

(v) a blaster-head sensor mounted upon each said blaster head, adapted to sense the absolute location and attitude of said blaster head, and sense objects in proximity to said blaster head;

(vi) a robotic controller adapted to receive, interpret, and record data from said blaster-head sensor and control the operation of said robotic blasting tractor with reference to a stored three-dimensional plan of the barge and fittings; and 16

(vii) an RF antenna mounted upon said robotic controller and said robotic blasting tractor, adapted to facilitate real-time communications;

where, in use, said positioning unit with said blaster head is moved along said transverse track beam, and said blaster head is moved in relation to said positioning unit, under the control of said robotic controller using real-time data from said blaster- head sensor with reference to the three-dimensional plan such that all unblocked surfaces of the barge bottom are reached with blast media.

12. The system for blast-cleaning a barge bottom of claim 11, further comprising a blaster-head camera.

13. The system for blast-cleaning a barge bottom of claim P , where said blaster- head sensor is further adapted to sense objects through a cloud of blast media.

14. The system for blast-cleaning a barge bottom of claim 11 , where said blaster- head sensor is further adapted to make sensor readings during pauses between pulses of blasting.

15. The system for blast-cleaning a barge bottom of claim 11, where said blaster- head sensor is further adapted to determine absolute location from fixed reference beacons placed inside the work building.

16. The system for blast-cleaning a barge bottom of claim 11 , further comprising a blaster-head camera, where video from said blaster-head camera is recorded and is combined with recorded data from said blaster-head sensor to provide for a detailed inspection of all surfaces and fittings of the barge bottom before, during, and after blasting. .

17. The system for blast-cleaning a barge bottom of claim 11, further comprising a blaster-head camera, where video from said blaster-head camera is recorded for later use in analyzing and investigating blasting operations.

18. The system for blast-cleaning a barge bottom of claim 11 , where the three- dimensional plan of the barge is obtained from an existing outside source.

19. The system for blast-cleaning a barge bottom of claim 11, where die three- dimensional plan of the barge is generated from the data obtained by said blaster-head sensors.

20. The system for blast-cleaning a barge bottom of claim 11, where said robotic controller prevents said blaster head from making contact with any object sensed by the sensors.