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Industrial Controls Automation for an International Shipping Company

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A Maritime Story

Most people think that industrial control systems only reside on factory floors and that PLC’s are only used to automatically control machines and communicate between ancillary plant equipment in the manufacture of a wide array of products. However, industrial control systems can also be found in many other applications besides those associated with manufacturing – even on the high seas.

One summer a few years ago, Connell Industries received a very interesting call from a shipping company. A Bulgarian freighter, the MV Traun, was sitting dead in the water in Savannah, GA due to failure of the ship’s air compressor control system. Because it was without air compressors, the ship could not turn over its massive diesel engines, nor could it steer, since compressed air was used to control the rudder.  The shipping company was hemorrhaging $130,000 each day the MV Traun was idle, making the ship’s air compressor repair a top priority.

freighter MV Traun.
The freighter MV Traun.

The biggest surprise wasn’t the stripped-bare compressor control panel.

Vincent DiGangi, the owner of Connell Industries, personally accepted this interesting challenge and flew down to Savannah to see if he could facilitate repair of the air compressor control system. He arrived at the dock and met with the ship’s captain and electrical engineer to get the details of what happened.  Vincent then went down below decks to the engineering compartment to examine the situation.  What he found was a big surprise – the air compressor control panel was stripped bare except for a few fuse holders, some relays and a power transformer on the back panel.  This left Vincent little to work with.

Fortunately, Vincent was able to get a set of drawings of the air compressor system. Unfortunately, they were all in Russian with very little English translation.  The saving grace was that all the symbols used on the drawings were internationally recognized.

After talking with the ship’s personnel, Vincent arranged to have the back of the panel and enclosure door shipped to Connell’s office in New Jersey. He then started laying out a new control design built solely from the Russian drawings and utilizing the intrinsic knowledge he had as to how high-pressure air compressor systems work.

Air Compressor Control Panel
Air Compressor Control Panel Stripped Bare

Installing and testing the new equipment onboard the ship

After a couple of weeks, Connell Industries had completely fabricated a new control panel and shipped it to Savannah.

Day 1 – September 21.

Vincent boarded the ship at 12 noon and immediately set to work.  The first order of business was to install the newly constructed back plate of the air compressor control panel and panel door to the existing enclosure. The next step was to reconnect all the wiring from the following locations:

  1. Control Room Switchboard
  2. Control Room Annunciator Switchboard
  3. (2) Compressor Motor Starter Control Panels
  4. (2) Hamworthy Compressors
  5. (2) 40 bar pressure vessels and the gauge / pressure switch panelboard

Day 2

Connell Industries tested the integrity of all the field devices and wire cable interconnections. Operating characteristics of the (2) compressor safety devices were verified for:

  1. High temperature air discharge protection safety
  2. Low oil pressure signaling safety
  3. Low oil pressure protection safety.

Connell then installed a temporary high temperature air discharge safety switch on Compressor #1.

Day 3

Tested the programmable controller wiring and communications configuration.  Next, Vincent developed the control logic sequence from the documentation provided by the ship’s electrical engineer.

Day 4

Installed and debugged the programmable controller system by:

  1. Testing and verifying manual system operation of both compressors – no protection
  2. Testing and verifying remote system operation of both compressors – protection
  3. Testing and verifying automation system operation of both compressors – protection

Testing next focused on the compressors for lead and lag control by:

  1. 1:2 and 2:1 with automatic switchover upon an active compressor shutdown sequence.
  2. Remote and Automatic selection from the control room operators station.

Tested and verified alarm notification on the compressor deck and at the control room operator’s station.

  1. Ensure all alarm signals were functioning and annunciated properly.

Once the installation was complete, a meeting was held with the ship’s Captain and Chief Engineer to arrange for the insurance agent to audit the installation and to verify the system’s completeness and operational readiness.

Completed Air Compressor Control Back Panel
Completed Air Compressor Control Back Panel

Day 5

The day started by meeting with the Captain, Chief Engineer and the auditor to run another series of verification tests on the compressor control installation.  A review of all the new drawings was conducted, showing the necessary additions made to comply with the National Electrical Standards. The audit focused on:

  1. Control Room operator station selector switch process for;
    1. Compressor Lead/Lag selection 1:2 and 2:1
    2. Remote and Automatic Selection Modes
  • Remote Start and Stop operations for compressors 1 and 2.
  1. Compressor control panel and main control panel
    1. Remote and Automatic control of compressors 1 and 2.
    2. Pilot light signaling and annunciation.
  2. Compressor control shutdown protection and alarm annunciation procedures;
    1. Simulated a low oil pressure alarm condition on compressor #1.
      1. Demonstrated proper compressor shutdown protection
  • Demonstrated proper alarm annunciation – audible and visual
  • Demonstrated control room operator station alarm annunciation

The audit was successful and new copies of the electrical system drawings were presented to the Captain. All in all, the whole installation and startup took only 5 days to complete and the MV Traun was certified to be seaworthy and was underway once again.

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