The DPSSNet is an easy to use tool which allows vessel crew to conduct network storm tests.
On a typical DP system a network storm should not have a detrimental effect on position keeping as there is typically redundancy in the form of dual networks.
The DPSSNet makes it quick and easy to conduct network storm tests on your DP system or other control systems. It does this by generating relevant packets of data to swamp the hardware under test. The DPSSNet is customised to meet the needs and requirements of each vessel and updates can be provided remotely.
The DPSSNet reduces the need for callouts to service engineers, reducing downtime and expense whilst being independent from the manufacturer.
What does the industry say?
"There have been a number of high-profile DP events attributed to failure of networks in the past. However, knowledge around the subject of DP related networks and their respective failures remains at the basic level for most stakeholders for example, designers, shipyards, OEMs, operators and those involved in DP FMEA management."
IMCA M 259 – Guidelines for the Management of DP System Network Storms
“The annual test of all important systems and components should be carried out to document the ability of the DP vessel to keep position after single failures associated with the assigned equipment class and validate the FMEA and operations manual.”
IMO 1580 – Guidelines for vessels and units with dynamic positioning (DP) systems 16 June 2017
“Network storms are a potential common mode failure capable of causing a drift off. All modern networks are fitted with protection against this type of failure. This protection must be checked periodically to confirm it is operational and that alarms to indicate that it is operating are working.”
MTS – TECHOP ODP 08 Annual trials GAP analysis
“Comprehensive tests for a network storm should be carried out during FAT and FMEA proving trials to ensure that such an event cannot fail both networks.”
MTS DP vessel design philosophy guidelines Part 2
“To this end, it will be necessary to carry out data throughput tests and network storm tests on each channel (Net A & B).”
MTS – TECHOP ODP 01
“The network functionality shall be verified in a test where at least the following items shall be verified:
…Worst-case scenarios – network storm”
DNV Offshore Standard DNV-OS-D202 Ch2. Sec 3 C501 and DNVGL-RU-SHIP Pt.4 Ch.9 January 2017
“In particular where the safety case claims that a dynamic positioning system achieves IMO Class 2 or better the duty holder for the safety case should investigate the communications architecture for the relevant DP system. If the dynamic positioning functions are dependent on a shared communication medium such as a dual data bus network, then the duty holder should ensure that appropriate measures are in place to prevent a single fault causing failure of the DP system.”
Health and Safety Executive UK - Safety notice OSD 1-2013.
Why select our solution?
Our unique solution allows the crew on board to conduct the testing with a cutting edge piece of hardware that is as simple as plug and play. Our solution has a one time cost and can be used many times. Alternative solutions involve flying an engineer to the vessel each time a test is to be completed. The one time cost of a DPSSNet unit is less than the cost of flying an engineer out just once!
The IMCA M259 document titled "Guidelines for the Management of DP Systems Network Storms" should be able to address most FAQs in relation to network storms in general. The most common FAQs concerned with the DPSSNet are detailed below.
1. Can you provide a visualisation that is data centric of the network storm?
There is an option to provide hardware to allow the real time monitoring and capturing of all network storm data. If desired, VT can post-process the captured data to provide charts of the network storm allowing the customer to see network storm and non-network storm flow into/out of the network. Note however that the key point of interest when performing a network storm is the effects (if any) it has on the system under test (SUT).
2. Does the hardware operate with XYZ system?
The DPSSNet hardware will operate with any system using Ethernet. Options are available to provide media converters/adapters as required.
3. Are you able to perform a test in the same manner as OEM X does?
Most likely yes. Please get in touch to discuss your requirements - firstname.lastname@example.org
4. What information do you need from us in order to perform a test?
Before performing testing, we will be in contact with you to discuss any requirements you may have. If information is required, it will likely be documentation such as a single line diagram of the system to be tested and a description of what the system does/what are the areas of concern.
5. What level of ability is required in order to perform the testing?
In order to access the unit, a very basic level of IT skills is required. We can provide a guide with pictures if this is required. In relation to the ability of the person performing the testing we would suggest referring to IMCA M 259 "Guidelines for the Management of DP Systems Network Storms" section 6 "Competency Profiles" profile C.
6. Do you provide the skills and ability required for profile B as defined in IMCA M 259 "Guidelines for the Management of DP Systems Network Storms"?
7. What happens if the testing results in a scenario are not as expected/not acceptable in terms of redundancy concept of the vessel?
Should such a scenario occur we can provide the information required to the OEM to allow them to investigate the issue further. If the OEM is unable to assist, then we may be able to provide assistance/suggestions on ways to move forward.
8. I have system XYZ, will my system "pass" a network storm test?
It is not possible to answer such a question without testing the system. Experience shows that just because OEM X’s system had no issues on vessel A does not mean that no issues will be found when testing the same OEM’s system on vessel B.
9. I understand that DPSSNet is designed to be able to be used by vessel crew, however is it possible to have an engineer attend in order to provide a network storm testing service to us?
10. Do you create a network storm of "junk" or "meaningful" data as set out in IMCA M 259?
We can create either, however, if the worst case failure is to be tested for, we would recommend testing with meaningful data for the system under test (SUT).
11. I have an urgent requirement to test a system, can you assist in having it tested asap?
Almost certainly, we can have the hardware shipped on the 1st available flight. Please get in touch to discuss your requirements - email@example.com