Welding Positions

Dear Readers,

In Construction Industry any conversation around welding starts with a discussion on welding position, it is mandatory to qualify the welder. At site welding activity starts with welder qualification. The American Welding Society (AWS) has defined the four basic welding positions. The same positions is followed in construction as well as welding related industries.

The four basic welding positions are: flat, horizontal, vertical, and overhead. An Alpha numeric is used to identify the position. Eg. 4F & 2G First number is used to define the position and alphabetic is used for the weld.

1 = Flat Position

2 = Horizontal Position

3 = Vertical Position

4 = Overhead Position

F = Fillet Weld

G = Groove Weld

1 refers to a flat position, either 1F or 1G

2 refers to a horizontal position, either 2F or 2G

3 is a vertical position, either 3F or 3G

4 is an overhead position, either 4F or 4G

The 1G and 5G horizontal and 2G vertical positions refer to the pipe position.

6G is an inclined position

Flat Position Welding: This type of welding is performed from the upper side of the joint. The face of the weld is approximately horizontal. The common term for this kind of weld is called, 'flat position' but it is also referred to as the 'down hand' position.

Horizontal Position Welding: In horizontal welding, the weld axis is approximately horizontal, but the weld type dictates the complete definition. For a fillet weld, welding is performed on the upper side of an approximately horizontal surface and against an approximately vertical surface. For a groove weld, the face of the weld lies in an approximately vertical plane.

Vertical Position Welding: In vertical position welding, the axis of the weld is approximately vertical. When welding is done on a vertical surface, the molten metal has a tendency to run downward and pile up.

Overhead Position Welding: Overhead welding is performed from the underside of a joint. In overhead welding, the metal deposited tends to drop or sag on the plate, causing the bead to have a high crown.

The welding positions explained above are commonly used by codes and industrial practice when qualifying welders and job execution.

For More Details about Welding Click Here

Weld Joints

Welds are made at the junction of the various pieces that make up the weldment. The junctions of parts, or joints, are defined as the location where two or more members are to be joined. The five basic types of welding joints are listed below.

 

1). Butt Joint (B). A joint between two members lying approximately in the same plane. 

2). Corner Joint (C). A joint between two members located approximately at right angles to each other in the form of an angle. 

3). Edge Joint (E). A joint between the edges of two or more parallel or mainly parallel members. 

4). Lap Joint (L). A joint between two overlapping members. 

5). Tee Joint (T). A joint between two members located approximately at right angles to each other in the form of a T.

In order to produce weldments, it is necessary to combine the joint types with weld types to produce weld joints for joining separate members. Each weld type can not always be combined with each joint type to make a weld joint. Below table shows the welds applicable to the basic joints.

For More Details about Welding Symbol Click Here

For More Details about classification of Electrode Click Here

Classification of Locomotives

Dear Readers,

We are regular traveler through railways, how many of us noticed the letters mentioned in engines? And what is the abbreviation of the same? Let us discuss about the classification of locomotives.

Locomotives are classified according to their track gauge, motive power, the work they are suited for and their power or model number. Each locomotive Class Name will consist of three or four alphabets followed by a number and then an optional alphabet or two. Each of these letters can be said to be a “slot”, which can be filled by a predefined set of alphabets or numbers to denote some characteristic of the loco. The Class Name can be found painted on the front, back and sides of the loco.

 The first letter denotes the track gauge. The second letter denotes their motive power (Diesel or Electric) and the third letter denotes the kind of traffic for which they are suited (goods, passenger, mixed or shunting). The fourth letter used to denote locomotives' chronological model number.

The first letter (gauge)

W – Indian broad gauge (the "W" Stands for Wide Gauge - 5 ft 6 in)

Y – Meter gauge (the "Y" stands for Yard Gauge - 3 ft or 1000mm)

Z – Narrow gauge (2 ft 6 in)

N – narrow gauge (toy gauge) (2 ft) 

The second letter (motive power)

D – Diesel

C – DC electric (can run under DC overhead line only)

A – AC electric (can run under AC overhead line only)

CA – both DC and AC (can run under both AC and DC overhead line); 'CA' is considered a single letter

B – Battery electric locomotive (rare) 

The third letter (job type)

G – Goods

P – Passenger

M – Mixed; both goods and passenger

S – Shunting (also known as switching engines or switchers in the USA and some other countries)

U – Multiple units (EMU/DMU)

R – Railcars 

The Fourth Number – Power/Version and Fifth Letter – The Subtype

This number is called “Series” denotes different things for Diesels and Electrics. This number denotes the Horsepower rating of the engine as multiples of 1000 hp. So a 2 will denote a locomotive with an engine with more than 2000 – 3000 hp power rating for Diesel engines. However all Electrics and all non-BG locomotives, the Series notation just denotes the chronological version/model of the locomotive.

The fifth and in most cases the last letter is called a “Subtype” and is the most confusing of all. It can be a letter or a number and may arbitrarily denote anything from power rating to unique factors of the loco. The subclass annotation will be letters denoting incremental hp power in multiples of 100. “A” denotes 100 hp added to the 3000 hp, “B” denotes 200 hp, “C” is 300 hp, “F” denotes 600 hp and so on. 

For example, in "WDP4D":

"W" means broad gauge

"D" means diesel motive power

"P" means suitable for passenger service

"4D" means the locomotive's power is 4,400 hp ('4' stands for 4000 hp, 'D' denotes 400 hp more) 

Or, in "WAP 5":

"W" means broad gauge

"A" mean AC electric traction motive power

"P" means suitable for Passenger service

"5" denotes that this locomotive is chronologically the fifth electric locomotive model used by the railways for passenger service.

Hope All are enjoyed this article. Wish you All the Best and Have a Nice Day