DFDS crews get accurate and reliable RPM readings with custom XDi solution

Perhaps the most stylish way of travelling between Copenhagen (Denmark) and Oslo (Norway) is to book a ticket for a DFDS cruise ferry where you can enjoy the 275 nautical mile (509 km) crossing in great comfort with restaurants, bars, and comfortable cabins.

Behind the scenes, DFDS crews are constantly working to ensure a timely, safe, and comfortable crossing; a task that requires dependable equipment. Aboard the M/S Crown Seaways, however, crews were noticing fluctuating and incorrect RPM readings on the analogue indicators for the main engine turbochargers.

Even though the indicators were not DEIF instruments, Chief Engineer Flemming Bo Larsen on the Crown Seaways contacted DEIF to discuss the possibilities for a better solution that could overcome the problem.

“We asked for a new DEIF instrument to replace the existing turbo RPM meter,” he says. “In our discussions with the technical team at DEIF, it became clear that it was not only the indicator but also the frequency-to-analogue-signal converter box that was causing fluctuating and incorrect RPM readings for our turbochargers”.

Test solution quickly proves itself

In close cooperation with Flemming Bo Larsen, the DEIF team developed an XDi test setup with a DX1 and a library of test indicators with preconfigured interface profiles matching the sensor type. An XDi test unit with the indicator library preinstalled was then installed on board for a practical test.

Since each main engine has two turbochargers, the test setup included a double-input RPM indicator able to measure RPM pulses from both turbochargers and show both results on the same screen. This indicator was used for the initial test on board.

“We replaced one of the existing RPM indicators with the XDi test unit,” says Flemming Bo Larsen. “We connected the sensor signals from both turbochargers on main engine 1 to the XDi. Right after installation, we got a clear and very stable RPM reading compared to the original system. The numeric readout allowed us to follow the rotation of the turbocharger down to around 100 RPM when the engine was stopped”.

After the initial test, the crew requested additional functionality from the new XDi library. These requests were swiftly implemented by the DEIF team.

Accurate and reliable RPM readings

Since the indicator replacement, crews on the Crown Seaways have enjoyed much more reliable RPM readings from their engine turbochargers.

“We have now been sailing with the new XDi indicator system on main engine 1 for some time and it has proved to be very accurate and reliable,” says a satisfied Flemming Bo Larsen. “It was therefore an easy decision to upgrade our three remaining main engines with the same excellent solution”.

He notes that DFDS could have chosen to replace two existing indicators with one XDi (since one XDi can display two readings) but decided to replace each individual old indicator with an XDi, mostly to keep the existing control panel layout.