Tuesday, March 31, 2009

Wooden house of Minahasa an earthquake resistant construction

In Minahasa of North Sulawesi, people build houses mainly from wood. Minahasa is a region in northern part of Sulawesi island. There are a number of active volcanoes which often erupt and cause earthquakes. So, the house construction there is mostly made from wood.

The kinds of wood which Minahasan people use are coconut, lingua, cempaka and sometimes besi or merbau. Old coconut tree which is not productive anymore in producing palm oil will then be cut and converted into home building material.

Wooden house of Minahasa
Wooden House in Minahasa has got stairs to the upper floor at the front

The wooden house of Minahasa looks beautiful in terms of their architecture. Architecture is the art and science of buildings. Although the traditional builders of Minahasan wooden houses have never taken any formal education, their designs are really environmentally friendly and united with the nature. Tourists who visit Minahasa often buy these wooden houses in Woloan village. This village has exported their knock down wooden houses to many countries around the world.

Wooden house can be one of the best home materials due to its earthquake resistant properties but it is not fire resistant. To minimize the risk of burning, architects must apply new design approach to their wooden house by applying fire resistant materials to some parts of the house. This can include fire resistant drapes and wall paper, as well as kitchen room made of ceramic materials.

When the new approach has been applied to the design of an earthquake resistant Minahasan house, it will be able to enter wider market of worldwide wooden house trade. I hope. by Charles Roring in - Indonesia

Also read:

Thursday, March 26, 2009

Diving Boat General Arrangement Consideration

by Charles Roring in Manokwari of West Papua - Indonesia

dive-boat.jpgAs naval architects, we usually begin our project design with calculations. We tend to focus more of our attention on principal dimensions such as type of ship or boat, the length overall, breadth moulded, depth moulded and prismatic and block coefficient. It is true that such principal dimensions are needed by the ship or boat designer to carry out detailed calculations including the resistance, propulsion, structural strength and the cost of construction.

A boat type which needs special design consideration from naval architects is diving boat. Diving boat is used by scuba divers in various marine parks around the world for accessing the coral reef. Most of the corals are located in shallow sea water. Therefore, when naval architects want to design the boats, they need to consider some important factors below:

The depth of boat

Because the diving boat operates in shallow water the depth of the boat should not more than five meters. It is better to have a smaller depth so that the hull bottom, keel and the propeller will not hit coral reef.

Twin hull or catamaran

In recent days, naval architects have introduced twin hull design for diving boat. This is a very good breakthrough for safe operation of the diving boat in the marine protected areas. Besides twin hull boat or catamaran has smaller depth moulded, it also has better stability. Catamaran can go to coral reef whose depth from the sea surface is around or less than 3 meters.

Wider deck area

A diving boat needs a wider deck area which is needed by dive operators for the placement of air bottles, compressor. A wider deck area means better movement for the divers to move around.

Diving platform

This is a lower deck which is constructed at the back of the diving boat or yacht which scuba divers use to climb to the boat. Usually there is a small stair which connects the diving platform with the main deck

Small freeboard

Most diving boats have small freeboard with ladder installed on both sides of the boat. After diving, scuba divers can come up to the surface and climb the boat from port or starboard side of the boat.

Diving is a fun yet dangerous sport. Naval architects need to design a room in the boat which can be used as an "emergency hospital" in case of accidents at sea. Divers can become victims of shark. Therefore, adequate first aid equipment is needed in the boat beside the diving equipment.

There are still more factors such as the sewage system and propulsion unit which I need to explain in this article but I think I should write them in another article. Also read: Designing Lines Plan with Fastship and Fastship and Delftship for Naval Architects

Wednesday, March 25, 2009

Position of crew room on traditional fishing boat

by Charles Roring in Manokwari of West Papua - Indonesia
Naval architects who design fishing boats frequently have to face many conflicting factors. Fishermen in Europe like to have a wide deck area to enable them to work freely during operation. The superstructure of fishing boat is therefore positioned by ship designers at the forward end of the boat. As a compromise, the rooms for the crews are positioned below the main deck next to the fish hold.
In the contrary, fishermen in Indonesia and Malaysia prefer to have crew rooms and their kitchen on the main deck. As a result the size of the superstructure is bigger and occupies more than sixty percent of the main deck area of the fishing boat. For instance, if the proposed design of LOA is 12 meters with the breadth of 3.6 meters then the deck area of the boat will be around twenty square meters.
A new approach has to be given to new fishing boat designs in Indonesia and Malaysia where working area for the fishermen on the main deck needs to be enlarged. For a traditional fishing boat with four crews, at least two beds for the crews have to be removed from the main deck to the lower deck whereas the kitchen can still be maintained as it has been a traditional custom for the fishermen in Indonesia to have wet kitchen. The new fishing boat design should have at least fifty percent working area for the fisherman to improve their working condition and to allow for more fishing equipment to be installed on the main deck.
In addition, wood which has been the traditional material for boat building in Indonesia can still be used with some introduction of Fiber Reinforced Plastics or FRP materials on the superstructure and joints of the watertight bulkheads that divide main body the fishing boat into engine room, fish hold and crew room.
It is hoped that the new approach on the design of the general arrangement of the fishing boat will improve the productivity of the traditional fishermen in Indonesia. Also read: Super-tanker and the risk of oil spill at sea and Designing Lines Plan with Fastship

Tuesday, March 24, 2009

Super-tanker and the risk of oil spill at sea

23248.JPGSuper tankers have been part of oil trading since 1960s. They are responsible for delivering oil and gas from refineries or producing facilities to other ports around the world. The competition among companies and the increasing demand for oil and gas has been the driving force for the increasing size of the oil carriers.
Frequently these supertankers besides having to cross large oceans such as the Pacific and the Atlantic, they have to pass by narrow yet busy straits and ports. The availability of modern navigational equipment does not guarantee that the supertankers will be free from any risk of collision with other smaller ships or boats. It is the ships' crews who have to safely guard their ships to the unloading ports. Last year, there was a tanker accident in South Korea. Oil spill from this tanker caused huge environmental damage to the coral reef, the sea, the beach as well as the fisherman villages near the area of the accident. Early this year, a cargo vessel loaded with Portland cements, and full with fuel oil in its tanks, collided with a tug boat in Jakarta bay of Indonesia. The vessel sank and spill fuel oil into the sea. Some crews lost their lives. While beach clean up can be done immediately, the destruction in the coral reef environment takes tens or even hundreds of years to recover.
Naval architects, when designing, oil tanker are guided with rules from classification societies, marpol and state regulations. They usually design tankers that have several sections or cargo holds. Collision bulkhead is also drawn at the forward end of the ship. In addition, they also provide double bottom to ensure that the tankers are still safe in case of experiencing grounding. Double bottom, collision bulkhead and double hull are not fully safe in protecting the supertankers during incidents of collision or grounding. When a supertanker experiences severe damage on its collision bulkhead, cofferdam, and double bottom, it will definitely spill oil into the sea.
Another way that we can do to reduce the negative impact of oil spill at sea is to limit the size of supertanker. It is not wise to just follow the request of ship owner by designing 500,000 tons supertanker. Size restriction is needed to ensure that the tankers that we design will not cause massive pollution in busy ports or straights. 
by Charles Roring in Manokwari of West Papua - Indonesia

Monday, March 23, 2009

West Papua needs to develop its agriculture

by Charles Roring in Manokwari of West Papua - Indonesia

One of the visitors of my blog visited me this morning. His name is Jay Hersker. He is from Hawaii. I am personally quite familiar with the word Hawaii. It is where the University of Manoa is located. That campus has department of naval architecture where students from around the world go there to study off-shore engineering supported by ADB and East West Center.

Jay Hersker has been travelling across South East Asia for years. He went to Thailand, Malaysia and now he is in Indonesia. In his opinion, Thailand's development of agriculture is impressive. Thai people can export their surplus of fruit and rice to many countries. In their traditional markets, there are various kinds of fruits sold by vendors.

I and my friend Sylvester Saimar talked with him about sago and varieties of palm trees which are endemic in West Papua. Jay said that he wants to visit Papua University to see their Herbarium. The university also publishes a journal called Beccariana. Although this island has a good agriculture educational institution like Unipa, the agricultural development in West Papua is far from being advanced. More works need to be done to develop the agricultural sector of West Papua.

Saturday, March 21, 2009

Designing simple bedroom with Archicad

Archicad is a building information modeling software that is getting more and more famous at the moment. It is created by Graphisoft for Architects around the world. Designing a house or a building using Archicad is easy and fast yet many people still do not know many of the powerful features of Archicad.

In today's article, I am going to tell you about how to design a bedroom using wall tools and objects of Archicad. First, launch the Archicad from your desktop or laptop. If you do not have the software, go to and download the trial full version or the free educational version and install it on your computer. On your window screen, after launching the Archicad, create a new document. Then you have to locate the Wall tool located in the tool box. Draw a bedroom with the size of 5 meters by 5 meters as shown in the following picture.


When you have finished drawing the walls, you can continue by adding door and windows to the bedroom. You can select various kinds of objects provided in the Object tool.


Because it is a bedroom, you need to put a bed, a cupboard and some chairs and a table. All of them can be taken from the object library in the Object tool. When you can the objects, you might find that the position of the objects is not right. If you want to rotate it, right click your mouse and select the Move and then Rotate. Click the object which you want to rotate and rotate it.


Now, you have designed the bedroom using Wall and Object tools of Archicad. You can see the 3D view of your bedroom by right clicking your mouse and select View all in 3D. The inside of the bedroom should look like this.


You need to study more features of Archicad if you want to design a better finishing for the bedroom.

This Archicad Basic Tutorial is written by Charles Roring in Manokwari of West Papua - Indonesia

Friday, March 20, 2009

Creating a rounded corner wall with Archicad 12

by Charles Roring in Manokwari of West Papua - Indonesia

Graphisoft's new release of Archicad 12 has been a great tool for architects who find that this software has helped them a lot in their daily works. Archicad 12 provides various new features such as curtain wall, hotlink module management and 3D document and etc. Anyone who has studied the fundamentals of building technology can design their own house using this software.

In this article, I am going to explain how to create a rounded corner wall with Archicad 12. Home owners some time ask their designers to round one of the wall corners of their new house which is usually the front one. To design a rounded corner, make two walls by clicking the wall tools on the tool box located on the left of your window screen. Then, one the working sheet, draw a vertical wall and a horizontal wall.


After drawing vertical and horizontal walls that form a corner wall, then proceed to drawing the round wall by clicking the use three points rounded wall, click and the outer ends of the walls. When you have clicked the two ends, Archicad will show a circle with a radius showing how the rounded corner wall will look like.


You need to make adjustments to the length and radius of the rounded wall so that you can connect the two horizontal and vertical walls. When you have finished making the adjustments, then you can press enter. Archicad wil show you an image similar to the one below. Make sure that the corner radius is not larger or smaller than it should be. You can see the final image of your wall in 3D if you select the view in 3D feature provided by Archicad 12 in view menu.


Archicad 12 is a great tool that accelerates the design process of a building. It is a BIM application software which I would like to recommend to anybody who is interested in learning how to design a house or a building in a fast yet accurate way.

Thursday, March 12, 2009

Fastship and Delftship for Naval Architects

by Charles Roring in Manokwari of West Papua - Indonesia

delftship-hull.jpgI have just downloaded a ship's hull development software called Delftship. This software is developed for naval architects who are working on ship design offices or students of naval architecture around the world. In my previous article, I said that I use Fastship to develop ship's hull. Fastship is made by Proteus Engineering while Delfship is by Delftship BV in the Netherlands.

Personally, the word Delft is a familiar word for me. It is the town where Delft University of Technology is located. This institution is very famous in my campus when I was a student of Teknik Perkapalan of Universitas Pattimura Ambon. My final assignment was the propeller design of a giant open hatch bulk carrier. I had to read books related to Ship's propulsion. One of the books which I used as my main reference was "Resistance, Propulsion and Steering of Ships." Although it is a very old book, I consider it as a very important book which students of naval architecture should read to widen their knowledge on ship design. The propeller data which is presented in the book is still valid at the moment. I used Troost B4-BP-d Series whereas the resistance is calculated using a method developed by J. Holtrop and G.G. J.Mennen.

Back to the hull development softwares, the availability of the free Delftship has given great opportunities to students of naval architecture around the world to experience an industry standard development of hull form at their own PC or laptops. Software companies which offer such scheme have indirectly promoted their software to young engineers who in the future will become professional ship designers and decision makers in maritime industry in their respective countries.

I will write more about these two softwares in the near future. In Fastship, besides it is a lines-plan software, it can calculate the resistance of ship. How about Delfship? Well, its manual says that it can calculate the GZ curve, stability curve, bending moment and shear force of a ship.

Sunday, March 1, 2009

Houses in Earthquake zone

by Charles Roring in Manokwari of West Papua - Indonesia

wooden-house-minahasa.jpgHouses that are built in active earthquake zone must possess high modulus of elasticity to withstand the ground movement. Usually for traditional houses, people use wood as the framework of their houses. Wood although strong and elastic in nature is combustible. Therefore, for modern building, walls are built from concrete whereas the wood pillars are covered with concrete or other non-combustible materials to prevent them from getting burned during a fire accident.

In tropical region, wood is one of the most favorite home building materials. Besides it is strong enough to support the dead and live loads of the building, wood can stabilize the indoor temperature of the house. Unfortunately, special design concept and wood treatment have to be applied to wooden houses to prevent them from being wholly consumed by the termite.

Earthquakes are mostly tectonic and volcanic. When a volcano erupts, it will release sulphur ash that is corrosive to metal roof. In Indonesia, villagers use earth roof tile or palm leaves as roofing materials. They are resistant to sulphur ash. Palm leaves are called daun atap or atap rumbia. They need to be replaced by new ones every three or five years. Sometimes during the rainy season, the owner of the house has to insert some new palm leaves to mend the leaks. Palm leaves as roofing material is very combustible. It is not recommended to be applied in big cities due to many electrical lines running near the roofs of the houses.

Houses that are constructed in earthquake zone are usually reinforced by the application of steel frames inside the concrete walls to prevent them from bending and fail during an earthquake.

In addition, the height of the walls which are normally 3.5 meters will be reduced to between 2.8 and 3.0 meters to minimize the risk of failure during the earthquake. Reducing the height of the walls will create an impression of hot in tropical houses. As a solution, many homes in quake zones have many windows that are reinforced with wood to support the dead loads of the wall and roof structure.

If I have to choose between wood and steel as reinforcing materials for home, I will choose wood. Also read: Archicad and Revit for House Design