Technical comparison

Before we continue with our comparison of ORIANA and VENTURA’s interiors and on board style next week we thought we would take a little time to look at the differences and similarities between another important aspect of the ships the engineering and technical side of the two.

Firstly below we have a comparison chart showing the general specifications of each ship.

 

While mostly overlooked by  shipping  for being one of a class of modern passenger ships VENTURA is in many ways a remarkable piece of machinery proving recently that she is able when the needed she can exceed her maximum speed even if not  the same margin achieved by ORIANA

To power her VENTURA has 4 Wartsila 12V46 and 2 Wartsila 8L46C engines when their total output is combined they produce 21,000kw, these power produce electricity to run all her on board AC machinery to supply power to the hotel services and also the ship’s 2 main propulsion motors.

Built by Dynamowerke these units each have a maximum speed of 150 revolutions per minute and have a shaft power of 21.000kw and are supplied by a voltage 4,250 volts AC

The motors are synchronous meaning that they rotate at a speed which is proportional to the voltage being supplied.

To enable the ship remain operational if a fault develops in either motors the units are divided into in to half motors.

 VENTURA's starboard engines.

One of VENTURA's propulsion motors.

On board ORIANA in comparison main power is supplied by 8 medium speed diesel engines in the  “father and son arrangement” built by MAN B&W which combined generate a total of  47,750kw 2 of these engines are connected via clutches and gearboxes to  the propeller shafts which when augmented  by booster motors to allow ORIANA to easily achieve speeds in excess of her service speed of 24 knots with each shaft producing 28,000hp.

  One of ORIANA's engines seen from above.

The remainder of the engines act as auxiliaries and provide her on board power for her electrical systems and hotel services in the event of a problem with auxiliary engines her main engines can power shaft driven generators arranged through the main engines gearbox.

Being very different sized ships is obvious that the two have slightly different fuel storage capacity VENTURA having 3200 tonnes compared with ORIANA's 2346 tonnes.
When ORIANA's fuel tanks are full this gives her a range of 5800 nautical miles (10748.467 km )
At a speed of 24knots ORIANA can travel 21 metres (69 feet) per gallon of fuel burned,
VENTURA in comparison when at cruising speed of around 17 to 18 Knots can cover 19.2 metres (63 feet) per gallon of fuel burned

Below the water line ORIANA propelled through the water by two 4 bladed 35 ton 5.79m (19ft) controllable pitch LIPS propellers giving the ship a faster response time to speed changes since the ship can be taken for example from All Ahead Full to Full Astern with out stopping and reversing the propellers direction.

    ORIANA's propellers and rudders during refit, 2004.

 VENTURA's propellers are 2 6 "skewed" bladed 5.6 metres each weigh around 16 tons and when at full revelation can propel  her at around 22 knots.
Being designed for regional cruising with only occasional repositioning cruises between Europe and the Caribbean she is generally not required to attain higher speeds only really requiring to so to avoid rough weather.

In these environmentally aware times ships need to play their part in reducing impact on the planet these range from small things such as energy efficient light bulbs to exhaust economisers and heat reclaim facilities.
 

In order to reclaim heat normally lost, both use a steam boiler plant which absorbs heat from the gases which is in turn used to produce steam which can then be used in a number of ways on board from heating and cooking in the galley, hot and cold water production for the hotel side of things to heating fuel before it is combusted in the ship’s engines

Below is a basic diagram showing  the type of vertical steam boilers used on board ship as a part of the heat reclaim system.

On board VENTURA the system comprises of two Danish built oil fired Aalborg vertical water tube auxiliary boilers with six exhaust economizers.

ORIANA features a plant that consists of two vertical down fired boilers, two Diesecon water-tube exhaust -gas boilers and two Diesecon twin water-tube exhaust gas boilers.
  
Photos Copyright: P&O Cruises.