# Mix and Match Power-Resistance for Tug-Barge

Discussion in 'Powerboats' started by aristonyoga, Sep 17, 2012.

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### aristonyogaJr. Application Engineer

Dear all,

I would make a table that summarized between tug boat power and barge towed deadweight for this range :

a. Range of tug boat length : 23 metres, 26 metres, and 29 metres
b. Range of tug boat power :
2 x 450 BHP
2 x 500 BHP
2 x 650 BHP
2 x 850 BHP
2 x 1000 BHP
2 x 1100 BHP
2 x 1200 BHP
c. Range of coal barge towed :
230 feet (3500 DWT)
240 feet (4000 DWT)
270 feet (5500 DWT)
300 feet (7500 DWT)
330 feet (10000 DWT)
365 feet (12000 DWT)

From that range, I would like make a table that summarized between length of tug boat, tug boat power, and barge size towed

I've try to using Maxsurf software. I create a barge model, calculate resistance at specific speed and draft, and calculate power requirement at specific propulsion efficiency.

The result is not same as I refer to Propeller Handbook (Dave Gerr) Chapter 8 - Tugs and Trawlers.

Methodology that I've used at Maxsurf software:
1. Create barge model
2. Calculate it resistance at specific draft and speed
3. Create tug model
4. Calculate it resistance at specific draft and speed
5. Sum resistance of tug & barge at specific draft and speed ---> total EHP
6. Calculate EHP --> DHP --> SHP --> BHP . I use total efficiency 40%

but the result is not same with Propeller handbook

Any idea how to calculate?I mean that can be a scientific formulation or any application formulation.