St_Stephen_Crane_Control_Site_Visit_Questions.docx

St Stephen Crane Control Site Visit Questions

1. Is the 120 day job completion date from award going to be extended? 120 day completion after signed approval drawings is more realistic for a job like this. It will take 4-6 weeks for the control manufactures to send out drawings and then your time to review them. Once drawings are approved it takes 6 to 8 weeks for the controls to be built and around 10 weeks for the motors. On site installation/ load test will take 3-4 weeks. Answer: The contract duration will be changed to 180 days.

2. I do not see the need to run any new conduit, the old conduit layout will work for the new controls and motors. We will install new seal tight flex and fittings to the new motors along with new conduit locking rings and bushings. Do we still need to provide a conduit layout drawing or can we provide a list of the size and type of wire. Answer: If existing conduit is re-used, there is no need to submit the conduit layout as long as the existing conduits are correctly sized for the new cables and are in good condition. If no conduit layout drawings will be submitted, contractor will need to provide a list of the cable name, size, type, length and associated conduits.

3. The bid specification doesn't specifically identify components / products by vendor name. However, it appears that they are specifically identified in the Bid Schedule (last page of the RTA Spec). Are we required to provide pricing using only the components / products called for in the bid schedule,(no Equal) or can we use 'like' components / products as long as they meet the specification requirements. Does the COE have a preference for the named products or is this data just illustrative? Answer: As long as the products meet the specification requirements, “approved equal” products can be used.

4. What is the size of the pipe for the conductor bar feed? Answer: The existing conductor bar is rated at 225A. The bus bar size is 1/4” x 3/4”.

5. What is the size of the wires for the existing conductor bar feed? Answer: the existing conductor bars is fed by 2/0 AWG cables.

6. Are we reusing the mainline disconnect, contactor, phase monitor and surge protection if the options aren’t exercised? Answer: Yes, if the options aren’t exercised, the mainline disconnect, contactor, phase monitor and surge protection will be reuse. The contactor shoes will be replaced per spec requirement.

7. Is the existing mainline disconnect set up for a ground connection? Answer: No, the ground is through the rail system.

8. How far apart are the existing supports on the current conductor bar system? Answer: the existing supports are not more than 5 feet apart.

9. Are we allowed to drill into the wall to install additional supports for the new conductor bar system? Answer: The existing bus for the bridge crane: 225 Amperes, 600VAC, 250VDC. Each section is 10’0” in length. Bus bar is ¼” by ¾”. Supports are every five feet. No tensioning is required.

The only reason the option would be exercised is if the existing bus system is not adequate to satisfy the electrical loads or if the addition of a 4th conductor is to the government's advantage. If the option were to be exercised, the government would be interested is the lowest cost, least impact solution. With that in mind, it is not clear that a system requiring tensioning or the installation of different or additional supports is desirable.

Calculations in support of any new bus installation would be required -inclusive the design of the supports and their attachment to the powerhouse. The Contractor would likely be permitted to drill into the existing concrete for the purposes of installing new bus supports should this Optional Bid Item be exercised.

10. On page 8 of the full package it says the trolley brake leaks. A hydraulic brake needs to be replaced with a standard electric brake due to the use of radio and VFD controls. This is not currently specified. Please clarify how you would like this handled. Answer: Specifications have been revised to remove all bridge and trolley hydraulic brakes and replace with electric brakes.

11. Can we use a motor mounted disc brake for the trolleys and bridge? This will only act as a holding brake as the VFD’s will be doing the braking through the motor. Answer: Please see revised specifications which include a brake specification paragraph indicating the permissible brakes for use on trolley and bridge motors.

12. What voltage are the flood lights mounted on the crane? Answer: the flood lights are rated at 480VAC.

13. How many alarms are required? What functions must have independent alarms? Where will the alarms be mounted? Answer: Alarms/indicating lights shall be located at the operator control station as specified in section 41 01 20.73 26 paragraph 2.4.1. At the minimum, the operator control station shall have the following alarms: Crane Control (green), Radio Control (blue), Brake Failure (red), Drive Failure (red), Emergency Stop (red).

14. SECTION 41 01 20.73 26 Page 23 2.6. Are there emergency stop pushbuttons located anywhere other than on the crane? Answer: Yes, there are four total. One in the erection bay and one at each of the three access landings to the unit from elevation 57.

15. SECTION 41 01 20.73 26 Page 22 Are lithium ion batteries acceptable for the radio? Answer: Specification section 41 01 20.73 26 paragraph 2.5.3.5 requires sealed nickel metal hydride battery.

16. SECTION 41 01 20.73 26 Page 22 2.5.3.6 Are we supposed to supply power to the box for the charger? Answer: No, specification 41 01 20.73 26 paragraph 2.5.3.6 requires the storage cabinet to be furnished with provision for connecting incoming AC power leads via conduit only. However, the requirement to have provision for incoming AC power leads has been removed from the specification.

17. Some of the requested items on the HMI like hertz and amp draw will add considerably to the cost (load cell readout no problem). Can we break these out as separate line items on the bid? Answer: Yes, the requested items on the HMI can be broken out on separate line items.

18. Since a ground bar is not available who will be responsible if that option is not exercised and the system has too much feedback to get a clean readout from the encoder? This may or may not be a problem depending on local power. Answer: Contractor shall coordinate with Project to ensure proper operation of the crane.

19. How are we to bid the length of the job? Is 120 days flexible or must we compete it in 120 days no matter what? How will this be weighted in the evaluation? Answer: The contract duration will be changed to 180 days.

20. Will the solicitation due date be pushed back as time will be needed to adapt the bid to the answers to these questions? The due date was extended to March 28th.