Pike River Coal is due to finally start earning this week after testing the patience of shareholders with years of delays.

A 20,000-tonne shipment of hard coking coal - worth $3.4 million - is due to get loaded at Lyttelton a quarter of a century since the West Coast mine was first seriously envisaged.

Since being spun out of New Zealand Oil & Gas and listing in July 2007, Pike River Coal has twice been forced to raise more capital and another capital raising of up to $45 million is looming.

In 2006, before its delayed float, the company said it hoped to hit coal the following year. Tunnelling delays put this back a year and ramping up to full production is stretching to 20 months.

McDouall Stuart head of research John Kidd said it was time for Pike to "get some runs on the board".

The company needed to correct its behaviour of being "a serial offender in over-promising and under-delivering".

Until it did the share price would be suppressed.

The first shipment is just a week's worth of full production, but Pike River's chief executive, Gordon Ward, said it was a significant milestone.

"While it's smaller than what we'll be doing going forward, it's still important for us."

The shipment was being sold to 10 per cent shareholder Gujarat NRE of India, one of two Indian life-of-mine customers committed to taking 55 per cent of production at market rates.

Ward said cost blowouts were common in new mine projects.

"We fully realise that the mine has taken a lot longer than was expected and the cost to do so was higher than anticipated but that's not unusual."

Development costs had blown out by about $50 million to $270 million.

"There's wins and losses with these things. There's been cost pressures but not as much as the coal price has had to have gone up."

Hamilton Hindin Greene broker James Smalley said that in the mid-1980s investors bought into NZOG with an eye to Pike.

"Part of their reason was to get exposure to a Pike River Coal development. The delays have been a bit frustrating, along with the need for additional capital."

The company is not discussing further capital raising or the progress of its deal with financier Liberty Harbor which it has asked to to extend a production condition on a US$27.5 million ($39.4 million) bond to June 30.

The company did say last November that it would need to raise $20 million more for working capital because of delays to full production.

There has been silence since but Kidd said between $35 million and $45 million may be required.

"They have been testing the market. When that confidence is restored will depend on when Pike reaches the numbers in the IPO document."

That assumed it would be mined at an average rate of one million tonnes a year over 18 years.

The delay in moving to full productionhad worked in Pike's favour. Althoughit missed 2008's astronomical prices fromhard coking coal, the current US$128 atonne was at the bottom of the cycle.

Prices for the coal - which is used to fuel steel furnaces - in the coming year are expected to be set at between US$160 and US$200 a tonne.

Ward said using the the company's formula for valuing the resource over 18 years (an average price of US$140 a tonne and a 59c exchange rate) meant there was more than $4 billion worth of coal in the mine, 50km northeast of Greymouth.