Single-Track Portal
Suitable for branch lines, narrow gauge, mountain routes and older main lines. The smaller opening is easier to integrate into a narrow hillside or rock cutting.
Gauge · Number of Tracks · Curves · Overhead Line · Architectural Style
Choose Tunnel Portals – Determine the Correct Gauge, Number of Tracks and Style
Find the right model railway tunnel portal for a branch line, main line, narrow-gauge railway, overhead-line operation, modern high-speed route or individually built tunnel entrance.
The Visible Face of a Hidden Railway Route
Which Tunnel Portal Suits My Model Railway?
Choosing tunnel portals by gauge, number of tracks and style begins with the technical railway route. The portal must suit the model scale, the track system, the number of tracks, the position of curves and the largest vehicles that will operate through it. Only then should the masonry, era and scenery theme be selected.
The external dimensions stated for a product do not automatically describe its free internal opening. This is especially important when the portal is located on a curve: the ends of a long coach swing towards the outside while its centre moves towards the inside. A portal that is sufficiently wide on straight track may therefore be too narrow on a curve.
Electric locomotives add the height of the pantograph to the equation. A portal described as suitable for overhead lines makes planning easier but does not replace a practical check with the contact wire, supports and actual vehicle.
The visual decision comes last. Rubble stone often suits historic branch lines and mountain railways, concrete suits modern main lines, rock portals suit natural cuttings and facing or decorative panels allow individually constructed tunnel entrances.
gauge first
scale and vehicle profile determine the opening
test curves
push the longest coach slowly through the entrance
allow for the contact wire
do not forget the additional height
style comes last
technical requirements take priority over appearance
Technical Fit Before Visual Appearance
Choose a Tunnel Portal in the Correct Order
Selecting colour or masonry first risks ending up with an opening that is too small. The following sequence therefore begins with the vehicles and track geometry.
| Check | Key Question | Consequence for the Portal |
|---|---|---|
| 1. Scale | Which model scale is being used? | Wall texture and basic dimensions must suit H0, TT, N, Z or G. |
| 2. Model Track Gauge | Standard gauge or narrow gauge? | H0m and H0e require a different profile from standard-gauge H0. |
| 3. Number of Tracks | Does one track or do two tracks pass through the opening? | Check the portal width and, with two tracks, the track spacing. |
| 4. Track Alignment | Is the portal on straight track or on a curve? | Curves require additional lateral clearance for long vehicles. |
| 5. Traction | Will electric locomotives operate beneath visible overhead wiring? | The opening, contact wire and pantograph require sufficient height. |
| 6. Prototype | Which era, region and route type are being represented? | Only now should natural stone, rubble stone, concrete or rock appearance be selected. |
Do Not Confuse External Dimensions with the Clear Opening
A product width of, for example, 13 centimetres does not mean that the free opening is also 13 centimetres wide. The actual internal opening at track level is what matters.
Branch Lines, Main Lines and Separate Tunnel Bores
Single-Track or Double-Track Tunnel Portal?
The number of tracks affects more than the width. It also changes the visual character of the structure and the type of railway scene for which it is suitable.
Double-Track Opening
Suitable for main lines and larger layouts. Track spacing, passing vehicles and overhang on curves must all be checked together.
Two Separate Tunnel Bores
Two single-track portals may look more convincing than one wide opening on mountain routes that were doubled later or on certain modern tunnel projects.
Flexible Portal Kit
Some kits can be assembled for one or two tracks. They are useful when the wing walls and opening need to be adapted individually to the track plan.
Check the Opening with the Actual Vehicles
Allow for Clearance, Track Curves and Overhead Lines
A portal can look correct to scale and still be too tight for reliable operation. The safest method is to position a temporary portal template and test it with the longest vehicle.
| Operating Situation | Area to Check | Suitable Test |
|---|---|---|
| Straight Track | vehicle width, roof and lateral safety clearance | slowly push the tallest and widest vehicle through |
| Portal on the Outside of a Curve | outward-swinging vehicle ends | guide the longest coach past the portal and wing wall |
| Portal on the Inside of a Curve | lateral displacement of the vehicle centre | observe the centre of the coach at the narrowest point |
| Double-Track Curve | two long vehicles passing each other | position vehicles on both tracks at the same time |
| Overhead Line | contact wire, supports and pantograph | check with the pantograph in its intended operating position |
| Narrow Gauge | smaller prototype loading profile at the same scenery scale | compare an H0m or H0e portal directly with the actual vehicles |
Current NEM guidance, manufacturer dimensions and the actual track plan are decisive for technical limits. A practical test run remains essential.
Avoid Positioning the Portal on the Tightest Radius Where Possible
A short straight section before the tunnel entrance improves operational reliability and often looks more prototypical. Where this is impossible, the opening must be made correspondingly more generous.
Match the Masonry to the Region, Era and Railway Route
Select the Right Architectural Style for the Tunnel Portal
Once the technical opening has been established, the portal can be matched to the prototype being represented.
Natural Stone and Rubble Stone
A versatile choice for historic main lines, branch lines, mountain railways and rural scenery from Eras I to VI.
Brick Masonry
Especially suitable for towns, industrial districts and northern German or British-influenced railway settings.
Concrete and High-Speed Designs
Clean lines and large openings suit modernised main lines, high-speed routes and more recent eras.
Rock and Scratch-Built Portals
Rock castings, decorative panels and portal facings allow custom openings and especially close integration into individual landscapes.
| Layout Theme | Suitable Portal Character | Suitable Addition |
|---|---|---|
| Historic Branch Line | single-track, rubble stone or brick | small wing walls, soil and dense vegetation |
| Mountain Railway | natural stone, rock portal or separate bores | rock face, scree and protective retaining wall |
| Classic Main Line | large stone portal with sufficient overhead-line height | tunnel lining, cable ducts and signals |
| Modern High-Speed Route | concrete or high-speed portal | overhead line, emergency walkway and technical equipment |
Distinguish Scale, Model Track Gauge and Vehicle Profile
Tunnel Portals for Standard Gauge and Narrow Gauge
The current shop selection is strongest in H0, TT, N, Z and G. For S, Gauge 0 and Gauge 1, construction panels, rock moulds and individually built portal openings may be useful alternatives.
| Gauge | Scale | Typical Model Track Gauge | Selection Note |
|---|---|---|---|
| Z | 1:220 | 6.5 mm | use fine portals or facing portals with very small openings |
| N and Nm | 1:160 | 9 mm or narrow gauge | single- and double-track portals plus modern high-speed styles are available |
| TT, TTm and TTe | 1:120 | 12 mm or narrow gauge | do not substitute an H0 portal simply because its physical size appears similar |
| H0 | 1:87 | 16.5 mm | widest selection of stone, concrete, kit and overhead-line portals |
| H0m , H0e and H0f | 1:87 | 12, 9 or 6.5 mm | select dedicated narrow-gauge portals despite the identical scenery scale |
| S, Sm and Se | 1:64 | 22.5 mm or narrow gauge | openings are often constructed individually from panels or castings |
| Gauge 0, 0m and 0e | usually around 1:45 | 32 mm or narrow gauge | allow for a large opening and sufficiently wide maintenance access |
| Gauge 1, Im and Ie | 1:32 | 45 mm or narrow gauge | portals are often built as stable but lightweight custom structures |
| G and IIm | prototype-dependent, often around 1:22.5 | frequently 45 mm | consider weather resistance and drainage on outdoor layouts |
Portals, Tunnel Linings and Portal Kits
Manufacturers of Model Railway Tunnel Portals
Manufacturers differ in material, architectural style, available gauges and the scope of their portal sets.
Single-Track, Double-Track, Narrow Gauge, Concrete and Scratch-Built
Open the Complete Tunnel Category
Tunnel Portals Directly from Modellbahnshop
Filter the portal selection by gauge, manufacturer, number of tracks, overhead-line or narrow-gauge operation and architectural style. Additional products are loaded from both pages of the current English tunnel category and checked for reachable, non-archived product pages.
Portal Type
The verified product selection is displayed.
NOCH · H0 · Single-Track
NOCH 58051 PROFI-plus
Stone portal for H0 routes, including layouts with overhead lines.
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NOCH · H0 · Double-Track
NOCH 58052 PROFI-plus
Wide textured rigid-foam stone portal for two H0 tracks.
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FALLER · H0 · Flexible
FALLER 120559
Portal kit that can be adapted for single- or double-track operation.
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NOCH · H0 · Rubble Stone
NOCH 58247 Rubble-Stone Portal
Hand-coloured opening for classic railway scenery.
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NOCH · H0 · Set of Two
NOCH 60010 Portal Set
Two robust portals for a single-track H0 tunnel route.
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NOCH · H0 · Concrete
NOCH 58091 Concrete Portal
Clean modern form for a single-track railway route.
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NOCH · H0 · Concrete
NOCH 58092 Concrete Portal
Double-track concrete opening for modern main-line and urban routes.
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NOCH · H0m/H0e · Narrow Gauge
NOCH 58026 Narrow-Gauge Portal
Narrower rubble-stone opening in 1:87 scenery scale.
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NOCH · TT · Single-Track
NOCH 48051 PROFI-plus
Hand-coloured stone portal for TT branch and main lines.
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NOCH · TT · Double-Track
NOCH 48052 PROFI-plus
Wide TT portal with finely textured stone surface.
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Busch · TT · Single-Track
Busch 8840 Tunnel Portal
Compact portal for a single-track TT railway route.
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Auhagen · TT · Set of Two
Auhagen 13276 Portal Set
Two portals for steam and overhead-line operation.
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NOCH · N · Single-Track
NOCH 34851 Stone Portal
Small stone-wall opening for a single N-gauge track.
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NOCH · N · Double-Track
NOCH 34852 Stone Portal
Double-track N-gauge opening with stone-wall texture.
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FALLER · N · Set of Two
FALLER 272588 Portal Set
Two stone portals for a double-track N-gauge route.
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Busch · N · High-Speed
Busch 8195 High-Speed Portal
Modern double-track opening for overhead-line operation.
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NOCH · Z · Set of Two
NOCH 44420 Portal Set
Two compact portals for a Z-gauge railway.
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NOCH · Z · Portal Facing
NOCH 44800 Portal Facing
Double-track portal facing for individually constructed entrances.
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Busch · G · Large Scale
Busch 8610 Tunnel Portals
Large portals for indoor and garden railway layouts.
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Woodland · N · Rock Appearance
Woodland WC1153
Two plaster portal castings that can be individually coloured.
View Product →Plan the Portal, Tunnel Lining and Landscape Together
Complement the chosen opening with tunnel lining, wing walls, rocks, scree and a permanently accessible maintenance area.
All Tunnel Products
Portals, ready-made tunnels, corner tunnels and interior walls.
Walls & Construction Panels
Wing walls, rock textures and individually built openings.
Filler & Plaster
Shape portal edges and terrain transitions.
Paint & Weathering
Add masonry colours, soot and moisture staining.
Overhead Lines
Allow for contact wire and pantograph clearance inside the portal.
Scree & Ground Material
Blend the tunnel entrance naturally into the foot of the mountain.
Trees & Plants
Add scale vegetation to the portal slope and rock cracks.
Model-Building Adhesives
Fix portals, rigid foam, walls and scenery securely.
From Vehicle Testing to the Final Product Choice
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Find the Right Tunnel Portal in Eight Steps
This sequence prevents an attractive portal from later proving technically unsuitable.
Determine the Scale
Scale
Clearly Define H0, TT, N, Z or G
Portal texture and dimensions must suit the visible model railway world.
Identify the Model Track Gauge
Vehicle Profile
Treat Standard Gauge and Narrow Gauge Separately
H0m and H0e use smaller tunnel portals than standard-gauge H0.
Select the Number of Tracks
Route Type
Single Track, Double Track or Separate Bores
With two tracks, also check the actual track spacing.
Test Curve Clearance
Clearance
Move the Longest Coach Through the Portal Area
The vehicle ends and centre must not touch the portal.
Allow for the Overhead Line
Electric Operation
Check the Contact Wire and Pantograph Together
The portal height must suit the planned contact-wire position.
Define the Prototype Theme
Design
Match the Era, Region and Route Type
Branch lines, Alpine routes and high-speed lines require different structures.
Compare Product Dimensions
Fit
Evaluate the Internal Opening Rather Than the External Dimensions
A cardboard template makes it easier to check the actual installation location.
Plan the Accessories
Project Completion
Add Tunnel Lining, Walls, Paint and Scenery
The portal and visible tunnel tube should appear to form one complete structure.
Check the Fit Before Fixing the Portal and Mountain Permanently
Common Mistakes When Choosing a Tunnel Portal
A common mistake is to test only the locomotive. Long passenger coaches and articulated vehicles often need considerably more lateral clearance on curves. A pantograph can also reach well above the vehicle roof.
Another mistake is choosing solely by the printed model gauge. A portal may suit the nominal scale but still be too tight for the actual radius, track spacing or overhead line.
Finally, the portal should not be considered in isolation. Tunnel lining, wing walls, the mountain connection and maintenance access all need additional space behind the visible front.
Mistake 1
Reading the External Width as the Opening Width
Check the actual clear passage separately.
Mistake 2
Testing the Portal Only with the Locomotive
The longest coach often determines the required curve clearance.
Mistake 3
Confusing a Narrow-Gauge Portal with a Standard H0 Portal
The same scenery scale does not mean the same vehicle profile.
Mistake 4
Adding the Overhead Line Afterwards
Plan the contact wire and portal height together from the beginning.
Position the Portal Provisionally First
Permanently fix the portal and landscape only after successful test runs with different vehicles, passing trains and, where applicable, the planned overhead line.
Answers About Gauge, Opening, Curves and Architectural Style
Frequently Asked Questions About Choosing Tunnel Portals
These answers help with the number of tracks, overhead lines, narrow gauge, curve position and a suitable scenic appearance.
How Large Does a Tunnel Portal Need to Be?
The required size depends on the model scale, vehicle loading profile, number of tracks, curve radius and overhead line. The free internal opening is decisive, not the overall external dimensions of the product.
Can an H0 Tunnel Portal Be Used for H0m or H0e?
A large H0 opening may work technically but can look oversized. Dedicated H0m and H0e portals reproduce the smaller narrow-gauge loading profile more convincingly.
How Do I Check a Tunnel Portal on a Curve?
Position a temporary portal template and slowly move the longest coach through the area in both directions. Check both the vehicle ends and the centre of the coach.
What Is Important with a Double-Track Tunnel Portal?
In addition to the portal width, check the track spacing and two long vehicles passing each other. Additional lateral clearance may be required on curves.
How Can I Recognise a Portal Suitable for Overhead Lines?
The product description often explicitly states that the portal is suitable for overhead lines. The contact wire, supports and operating position of the pantograph must nevertheless be checked in practice.
Which Architectural Style Suits a Branch Line?
Single-track natural-stone, rubble-stone or brick portals are often particularly suitable. The region, era and surrounding retaining walls should use a coherent style.
Which Portal Suits a Modern Railway Route?
Concrete portals and modern high-speed designs suit contemporary main lines and high-speed routes. Technical details and suitable overhead wiring reinforce the modern appearance.
Are Two Single-Track Portals Better Than One Double-Track Portal?
It depends on the prototype. Separate tunnel bores can look more convincing on mountain routes doubled at a later date or on certain modern tunnel projects.
Do I Need a Tunnel Interior Wall Behind the Portal?
The area visible from normal viewing angles should be lined. This prevents bare layout construction or untreated wood from remaining visible behind the opening.
Can I Build a Tunnel Portal Myself?
Yes. Construction panels, rock castings, decorative panels and portal facings allow custom openings. The required technical clearance must remain fully available.
Which Type of Tunnel Portal Is Suitable for Beginners?
A ready-made single-track portal on straight track is particularly easy to work with. It can be tested easily and then supplemented with tunnel lining, walls and scenery.
When Can the Tunnel Portal Be Permanently Installed?
Only after successful test runs with all important vehicle types, the intended track spacing and, where applicable, the fully planned overhead line.
Check the Gauge and Clearance First, Then Choose the Architectural Style
Use the filters for gauge, number of tracks, overhead-line operation and portal type and then compare the actual opening directly at the planned installation location.
Open the Main Model Railway Guide
Content reviewed on 16 August 2026. Product dimensions, the actual vehicles used, track geometry and the instructions supplied by the respective manufacturer remain authoritative.