Miscellaneous Errands

With all the PPC-1 project activities in place all that is left for the PPC-1 project management team are miscellaneous errands.  One of these tasks includes the electronic consolidation of all the relevant documents and files from the project for the ongoing use by the operations team.  Brett Worrall, Lee Harper, Robin Webb and John Bradfield in the Sydney CLS attended to tasks such as these on the New South Wales public holiday today.

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Inventory Checks

Alongside the B2 training, all three cable stations are completing their final inventory checks with the Tyco C&A staff.  This involves going through the inventory records and sighting and cross-checking the items, quantities and serial numbers – right down to every last washer, nut and bolt.

In the picture above, Matt is checking off the keys that are used to control the PFE to ensure that none are missing.

The successful completion of the inventory reports at all three cable landing stations is just one of the documents that need to be completed before PIPE and Tyco can close out the project.

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  • Fernley J Harris
    CHIEF ENGINEER. FI diag E. [CABLE SHIPS Retired.] Awsome cabling achievment undertaken by an exceptional team, belonging to a company of ...

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Fresh Air System

Fresh air systems in cable stations have three important functions.

First, they must provide fresh air.  If there is no fresh air then carbon dioxide from people builds up in the rooms.  If this happens then people cannot naturally operate in the rooms.

Second, they ensure that the air that is circulated in the rooms is clean.  The cleaning aspect of the fresh air system ensures that dirt does not penetrate the rooms in which the equipment is housed.  If dirt gets into the equipment then it can affect the performance of the equipment and consequently the system.  The fresh air system keeps the rooms clean by filtering the air that is circulated in the rooms.

Third, they have a fire suppressant role.  This role involves creating an effective seal in the event of a fire to ensure that the FM200 gas is effective.  Information about the FM200 fire suppression system was contained in a previous blog post which is linked to here.

Pictured above is a key part of the fresh air system.  From left to right the picture shows the: air intake box; electric axial fan; and the electric motor driven vent.  Above the vent are the pipes which connect to the air-conditioner.  The air intake box contains a filter which is replaced periodically.  The electric axial fan draws fresh air into the room.  The vent shuts air supply in the event of a fire.  In the event of a fire the air-conditioning and fresh air fan shut down immediately and the vent snaps shut to seal the system.  Then the FM200 goes to work.

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FM200 Fan Integrity Testing

In the archives there been various write-ups on the FM200 fire suppression system.  An area not discussed is the need to certify the various rooms for compatibility with their suppression system.  As discussed previously, compressed in the FM200 cylinders is enough gas to fill the room so that it is 100% protected.  For the system to work, the room is required to hold sufficient gas to cover the tallest piece of equipment in the room for 10 minutes.  The lower the equipment, the higher the roof, the larger the room, the less the penetrations – the better the FM200 can perform.

To certify the rooms, one doorway is sealed with an adjustable door seal with an integrated fan – see the picture above.  The fan is used to charge the room and the metrology measures the pressure variation between inside and outside the room.  In the Sydney Cable Landing Station the results achieved were excellent.  The submarine equipment room achieved ten times the requirement with a figure of 100 minutes and the data centres achieved an amazing 350 minutes!

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PFE Safety – Key Interlocks

As mentioned in previous posts, there is a high amount of voltage and current on our undersea cables which is supplied by our High Voltage Power Feed Equipment (HVPFE). Due to this high voltage and current generated by an HVPFE, it is critically important that safety procedures be followed at all times when working on this type of equipment.

One important feature built into our PFEs that helps to ensure that proper procedures are followed, and to protect workers when working inside is the HVPFE key interlocks.

These interlocking keys can only be released when certain steps are followed. For example in the above picture, you see key 1 directly above the high voltage switch in our PFE control bay. In order for Key 1 to be captive as shown in the photo, the adjacent converter bay must be powered down and breakers in the off position in order to “release” key 1 from that bay so that you can gain access to the high voltage switch in this bay.

There are multiple sequences like this that are followed when working on a PFE and these sequences will require that certain bays be turned off, certain modules be set to ground, etc, prior to continuing. It literally forces the technicians to put the PFE and the PFE module to be worked on into a “safe” state prior to commencing work.

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Lightning Protection

The area in which we have constructed our facility in Sydney is prone to summer storms with the associated risk of lightning strikes.  After discussions with our vendors we have included a number of lightning surge arrestors and discharge devices on our outside plant and facilities on the roof of the building.

Shown here is a gas tube discharge device used for the GPS antennas for the synchronisation devices.  It is from CITEL and we hope it does its job!!

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  • Eddie Saunders
    Having looked at the picture of the gas tube discharge device I can say that I have no issue with ...

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GPS Time Source

This is a photo of the 3100 and our NTP server which are both located in Sydney.

As discussed in an earlier entry one of the more important aspects in the network particularly in relation to transmission services is network synchronisation.

PPC-1 has a primary reference clock 3100 (PRC) that provide a highly stable time source and clock signal from which our NTP server and our transmission equipment receive their clocking. The device complies with UTUT G811. What this means in practice that we have a very stable clock (stable to better than 100 ns with respect to Universal Coordinated Time (UTC) when locked to a GPS signal, GPS Holdover Time Error: 8.6 µs per day (0 °C to +50 °C, ±5 °C) when not in sight of a GPS satellite.

In frequency terms, a clock signal at 2.048 Mb/s output frequency is accurate to better than: 1 x 10-12 with a GPS Holdover Stability of : 1 x 10-10 per day (0 °C to +50 °C, ±5 °C). This equipment is made by Symmetricom. It is not unique to PIPE as it used by all of the major carriers to synchronise their networks.

Slaved to this device to this device is our NTP server from where our NMS gets its time stamp network wide. Finally, and probably most importantly, our Cisco transmission equipment (ONS 15454) uses a clock signal from the PRC to time the SDH portion of the network and to propagate network clock signals among the ONS elements.

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  • Michael van der Koff
    Dear Robert, SDH networks require both sides to be sending AND transmitting at the same rate. This differs from the ...
  • Robert
    Why do you use an accurate time source instead of syncing receiver clocks using the edge of binary transitions or ...

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More on Seismic Zone 4 Installation Methods


It is also important to note that in some instances, a rack or bay must be tied into overhead racking. If this is required, we install what we call in layman’s term “Isolation Apples”, which is because they are red in color and look somewhat like an apple! These are made from a non-conductive ceramic type material, and during a seismic event, these will break and allow overhead racking and equipment racks and bays to still sway independently. They also help to isolate the bay from the overhead racking electrically, which we will be discussed in a later post.

In addition to the installation method used by installing the racks / bays as free floating, we also need to look at “how” they are secured to the floor. For the bolts, we use Hilti bolts that are also rated for seismic zone 4. Basically, they are a sturdier bolt, and they also are drilled deeper into the concrete, thus giving us more holding power at the bottom of the racks / bays which is what we need for the high seismic zones.

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Seismic Zone 4 Installation Methods

As discussed in a previous blog entry on 18 June, an important engineering requirement for us on our network is installing racks that are NEBS seismic zone 4 compliant.  To explain this further, it is important to understand that while having racks that are rated for seismic zone 4 is crucial, if they are not installed correctly they will still fail in their purpose!  Thus, in addition to the engineering of the racks, we must also insure that the proper installation methods are followed.

On PPC1, the standard that we follow for seismic 4 installations is that the racks / bays are all installed as “Free Floating.”  What this means is that our installed equipment racks and bays are not bolted into the overhead iron work or ceilings and are secured to the floor only so that they can “Sway” during seismic activity.

So the next question on everyone’s mind is why not brace the racks from both the bottom and the top to make them more secure?  To answer this, it is first important to understand that during seismic activity, structures tend to sway independently and in different directions.  In a cable station, our overhead iron work in most instances is installed as an independent free floating structure (see above photo.)  This is done by installing the racking and hanging it from the concrete ceiling only and not tying it into any side walls.  The entire structure is then free to “sway” during any seismic activity.  So, in regards to overhead racking and equipment racks, we want to keep them separated so that the racking can continue to sway independently, as well as allow our bays to sway independently.  If we were to secure the racks both at the bottom to the floor as well as at the top to the overhead racking, we have the potential for failure of one structure or the other when they start trying to sway in different directions.

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  • Chad Leverington
    "She then continues her way north until Madang" "We have people on her who report back to us daily" so ...
  • Brett Worrall
    Sorry guys, we are all spread out over the place at the moment and the blog has suffered. The Durable ...

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Watching the Network (Part 2)

The SNMPc software comprises 2 parts: the core application and an add-on web portal for more sophisticated graphing and reporting options. We are currently running through the initial deployment and have the core software up and running. The web portal aspects will be added in the next couple of weeks.

The SNMP traps will be the primary reporting and monitoring method for the network but we will also have a backup ‘dry contact’ alarm aggregation solution in the unlikely event that we lose SNMP visibility to any device.

When the deployment is complete we expect to have at least 75 discrete pieces of equipment, spread across 6 international sites.

 

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  • Alan
    Were open-source monitoring solutions considered? Personally, for most network and device monitoring I use a combination of Nagios and Cacti, with ...
  • Matt Whitlock
    Todd, The SNMP manager is giving us a high-level network view of everything (including plant and back office PCs/phones). For ...

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