CP Fitters' Phase 2 Apprenticeship Training

N-Type Material, P-Type Material.

When a semi-conductor material such as silicon is doped with certain impurities, we can end up with either N-type material or P-type material.

If we sandwich a layer of P-type material with a layer of N-type material, we end up with a diode.

If we add a further layer of either N-type material or P-type material, we end up with a transistor, either an NPN transistor or a PNP transistor.

Read more about doping here.

Located in Heritage Depot, Howth Demesne, Howth, Dublin 13.

From the website:

The Transport Museum Society of Ireland began with an abortive 1949 effort to preserve three Dublin trams. Totally voluntary, the Society became a limited company in 1971 and is now a registered charity, operating to international museum standards.
The museum is located in the Heritage Depot, Howth Demesne, Howth, Ireland. On 1st September 2001, the collection, increasing at an annual average rate of five, totalled 170 (average age 46 years). Sixty out of the 100 vehicles currently in Howth are on display, and others can be inspected by prior arrangement. The oldest items date from 1883, the newest 1984. Read More...

If you have Google Earth installed on your machine, download and open this file to view the museum's location.

Sat Nav Coordinates:
53°23'19.61"N  
6° 4'50.30"W

Some pictures from the Museum:

• On Friday, 20th July, 2012, twenty four apprentice CP Fitters paid a visit to the museum. You can see some pictures from this visit, and read more here...
• On Saturday, 25th August, 2012, the Museum held an open day as part of Heritage Week. You can see some pictures here...

From their website:

We are leading Builders Merchants and Hire Specialists, offering customers a huge range of timber, building materials, plumbing and heating supplies, plus a comprehensive plant,equipment and scaffolding hire service.

Read more...

Apprentices (Note: we have only begun recording apprentics here from cp12b, so there may be more than those listed)

• Fergal Weldon, g2cp12b

Company Contact: Evelyn Donegan

Term used to designate a particular side of a vehicle. With plant vehicles it is problematic to describe a side of a vehicle as 'driver's side' or 'passanger side'. This is because plant vehicles often don't make provision for passangers, or the steering wheel may be located in the centre of the vehicle.

To avoid this problem we identify the side of a vehicle by describing it as nearside or offside. The nearside is the side of the vehicle nearest to the side of the road, when the vehicle is driven on the road under normal conditions - think of the nearside as the side nearest the ditch. The offside is the side off away from the side of the road.

Corners of the vehicle may be described as follows:

• NSF: Nearside Front.
• OSF: Offside Front.
• NSR: Nearsdie Rear.
• OSR: Offside Rear.

Low friction bearing used in plant vehicle engineering. Similar in many ways to roller bearings, and like those bearings, needle roller bearings can only support radial loads. They cannot support axial loads.

Needle roller bearings are used in places where space restrictions prevents the use of ball bearings or roller bearings.

Used to support and sustain radial loads in places where space is seriously restricted and ordinary roller bearings will not fit:

In construction plant fitting, the term 'needle valve' is generally taken to refer to the needle like valve that is forced upwards on to its seat by the action of a float in a carburettor float chamber.

The function of the valve is to control the flow of petrol into the carburettor.

As the float chamber fills, the float rises and forces the needle valve on to its seat.

As the float chamber empties, the float sinks, allowing fuel in past the needle valve to fill the float chamber.

Needle valves are used in both diaphragm type carburetors and float chamber type carburetors on small plant engines.

Up until the mid 1970's many vehicles still used positive earth electrical systems - we bolted the positive terminal of the battery to the chassis, and fed all electrical components from the negative terminal. Before electronic components became common in vehicles, most of them used positive earth systems.

With the availability and reliability of cheap and efficient electronic (solid-state, no moving parts) components, it became necessary to switch to negative earth systems.

Electronic components and devices must use negative earth electrical systems. That is why modern vehicles all use negative earth systems - the negative terminal of the battery is bolted directly to the body and chassis of the vehicle.