A standard consist would usually be 18+ cars, 12 of which were to be Heavy Scout Cars (The lack of AA variants frequently reduced the number to 10). Some trains of this type only consisted of 8 Schwerer SchienenPanzer cars. While most of  these cars and trains were self propelled, a steam locomotive was sometimes used to push and pull these cars along.  the break down is thus:

Minimum requirements of consists used for combat operations in 1944 -1945: Can be configured as you wish.

German Armored Trains

Thanks to .matador models. co. for the detailed information below

Germany made use of armoured trains from the beginning of the Second World War. Extensive use was made of captured material, and new trains were built for the invasion of Russia in 1941. Military success was followed by lengthening supply lines, and armoured trains were needed to protect the railways from partisan activity. 
Attack, defence, patrol and maintenance of communications, even artillery support: there was a wide variety of potential roles for the armoured train. In May 1942 the decision was made to create a standard design of train - the BP42 - which, with a few improvements and modifications, was to serve to the end of the war. Eleven BP42 trains were constructed, and several older trains were re-configured to approximate to this standard, using the existing stock. Additional anti-tank firepower was later added, to make the BP44.

Composition
The complete BP42/BP44 train was symmetrical. In the centre was an armoured locomotive. This had an armoured tender behind, and an identical auxiliary tender ATG-2 in front to increase range. Next came artillery wagons ATG-3, each with some accommodation, for kitchen or medical purposes. The gun, a 7.2cm or 10 cm howitzer, was housed in a ten-sided revolving turret. Outside these came two nearly identical wagons. One was the infantry wagon ATG-5, and the other the command wagon ATG-4, nearly identical but distinguishable by minor differences in the roof plates and by its radio aerials. Outside these came an artillery and flak wagon ATG-6. The flak was the 2 cm Flakvierling, and the turret was identical with that of the artillery wagon. Armour for all units was between 1.5 and 3 cm. This extended down to protect the bogies. Articulating armour plates allowed the crew to move between the wagons under cover. The train's armament was strengthened by the addition of two tanks, to enable it to take the fight to the enemy. These travelled in tank-carrier wagons ATG-7 in a central well between the wheels, to give added protection to the running gear. A ramp at the outer end of the wagon enabled the tank to disembark rapidly. Typically two Czech 38T tanks were carried: not a match for the later enemy tanks, particularly in the East, but reliable, and highly effective against partisans. At either end of the BP42 was a pusher car ATG-8. This was essentially a flat car which was more expendable than the rest of the train and would hit trouble first. Facing the tank-carrier car a special automatic coupling enabled swift detachment so that the tank could be deployed more swiftly. The pusher cars were usually loaded with ballast and track-mending equipment. 

The BP44 was the improved version of the BP 42, introduced in 1944. The most visible change was the replacement of the pusher cars with Panzerjäger wagons ATG-9. Essentially these were flat cars with a low superstructure carrying the Panzer IV turret armed with the long 7.5cm KwK L/48 as seen on the Mark J. This gave some measure of protection against tank attack. Strengthening of the armour plate was largely precluded by the resulting weight increase. An order was placed for 46 Panzerjäger wagons, but may not have been fully implemented. Where possible the artillery turrets were to be up-armed with the 10.5cm Field Howitzer, or the 15cm howitzer. BP42 and BP44 trains were also provided with two Panhard Armoured Cars, able to operate normally but also supplied with alternative rail wheels for scouting along the tracks. The wheels not in use were typically carried in the pusher cars. 

Variations
We have depicted the typical equipment for the BP42 and BP44 types. Variations did exist. As the war progressed, designs of existing cars were simplified. There was also the continuing use of older material, upgraded and re-armed if possible to match the standard of the BP42/44 specification. There were also some later modifications. The 2 cm Flakvierling was in a few cases replaced by the Wirbelwind turret, which improved protection for the crew. At least one train, number 32, mounted 3.7cm flak guns. There were also minor variations between the armoured locomotives. On occasion the Czech 35 T, or the French Somua or Lorraine SP gun were used in place of the 38 T.

Conclusions
The BP42/44 trains were formidable weapons. They had considerable firepower in their own right and their crew of in excess of 130 men was able to launch effective infantry action with armoured support. They were ponderous, and in some situations found difficulty combating the guerrilla tactics of partisans. They were vulnerable to mine-traps, and their great firepower was at times not fully useable. As the tide turned against Germany they proved very effective in the defensive fighting and protection of rail communications from the advancing Russians.

Colour Schemes
BP42 trains appeared in a wide variety of colour schemes. The early examples were painted in Reichsbahn grey, a medium shade, paler than Panzer grey. Some sources state that Panzer Grey was used. Later photographs of the BP42, and all pictures of the BP44, show the standard yellow used for armour after 1943, with or without the over-spray of red-brown and /or green. As the complete trains were painted when set up, colour schemes tended to be consistent throughout and appropriate to the theatre of operations. In winter, trains appeared in white, though sometimes the 2cm flak guns retained their normal colour. As the allies gained air superiority, increasing use was made of camouflage. Late photographs show trains almost unrecognisable under piles of dense foliage.